making of a systems/network engineer.

OMG LVM

2011-04-20T20:09:00.000-07:00

The system has six SCSI hard disks, /dev/sda - /dev/sdf. /dev/sda is used for the Debian Etch system itself, while we will use /dev/sdb - /dev/sdf for LVM and RAID. /dev/sdb - /dev/sdf each have 80GB of disk space. In the beginning we will act as if each has only 25GB of disk space (thus using only 25GB on each of them), and in the course of the tutorial we will "replace" our 25GB hard disks with 80GB hard disks, thus demonstrating how you can replace small hard disks with bigger ones in LVM.

2 LVM Layout

Basically LVM looks like this:

Scenario with details :

You have one or more physical volumes (/dev/sdb1 - /dev/sde1 in our example), and on these physical volumes you create one or more volume groups (e.g. fileserver), and in each volume group you can create one or more logical volumes. If you use multiple physical volumes, each logical volume can be bigger than one of the underlying physical volumes (but of course the sum of the logical volumes cannot exceed the total space offered by the physical volumes).
It is a good practice to not allocate the full space to logical volumes, but leave some space unused. That way you can enlarge one or more logical volumes later on if you feel the need for it.
In this example we will create a volume group called fileserver, and we will also create the logical volumes /dev/fileserver/share, /dev/fileserver/backup, and /dev/fileserver/media (which will use only half of the space offered by our physical volumes for now - that way we can switch to RAID1 later on (also described in this tutorial)).

3 Our First LVM Setup

Let's find out about our hard disks:

fdisk -l

The output looks like this:

server1:~# fdisk -l

Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          18      144553+  83  Linux
/dev/sda2              19        2450    19535040   83  Linux
/dev/sda4            2451        2610     1285200   82  Linux swap / Solaris

Disk /dev/sdb: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdb doesn't contain a valid partition table

Disk /dev/sdc: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdc doesn't contain a valid partition table

Disk /dev/sdd: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdd doesn't contain a valid partition table

Disk /dev/sde: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sde doesn't contain a valid partition table

Disk /dev/sdf: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdf doesn't contain a valid partition table

There are no partitions yet on /dev/sdb - /dev/sdf.

We will create the partitions /dev/sdb1, /dev/sdc1, /dev/sdd1, and /dev/sde1 and leave /dev/sdf untouched for now. We act as if our hard disks had only 25GB of space instead of 80GB for now, therefore we assign 25GB to /dev/sdb1, /dev/sdc1, /dev/sdd1, and /dev/sde1:

fdisk /dev/sdb

server1:~# fdisk /dev/sdb

The number of cylinders for this disk is set to 10443.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): <-- m
Command action
   a   toggle a bootable flag
   b   edit bsd disklabel
   c   toggle the dos compatibility flag
   d   delete a partition
   l   list known partition types
   m   print this menu
   n   add a new partition
   o   create a new empty DOS partition table
   p   print the partition table
   q   quit without saving changes
   s   create a new empty Sun disklabel
   t   change a partition's system id
   u   change display/entry units
   v   verify the partition table
   w   write table to disk and exit
   x   extra functionality (experts only)

Command (m for help): <-- n
Command action
   e   extended
   p   primary partition (1-4)
<-- p
Partition number (1-4): <-- 1
First cylinder (1-10443, default 1): <--
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-10443, default 10443): <-- +25000M

Command (m for help): <-- t
Selected partition 1
Hex code (type L to list codes): <-- L

0  Empty           1e  Hidden W95 FAT1 80  Old Minix       be  Solaris boot
1  FAT12           24  NEC DOS         81  Minix / old Lin bf  Solaris
2  XENIX root      39  Plan 9          82  Linux swap / So c1  DRDOS/sec (FAT-
3  XENIX usr       3c  PartitionMagic  83  Linux           c4  DRDOS/sec (FAT-
4  FAT16 <32M      40  Venix 80286     84  OS/2 hidden C:  c6  DRDOS/sec (FAT-
5  Extended        41  PPC PReP Boot   85  Linux extended  c7  Syrinx
6  FAT16           42  SFS             86  NTFS volume set da  Non-FS data
7  HPFS/NTFS       4d  QNX4.x          87  NTFS volume set db  CP/M / CTOS / .
8  AIX             4e  QNX4.x 2nd part 88  Linux plaintext de  Dell Utility
9  AIX bootable    4f  QNX4.x 3rd part 8e  Linux LVM       df  BootIt
a  OS/2 Boot Manag 50  OnTrack DM      93  Amoeba          e1  DOS access
b  W95 FAT32       51  OnTrack DM6 Aux 94  Amoeba BBT      e3  DOS R/O
c  W95 FAT32 (LBA) 52  CP/M            9f  BSD/OS          e4  SpeedStor
e  W95 FAT16 (LBA) 53  OnTrack DM6 Aux a0  IBM Thinkpad hi eb  BeOS fs
f  W95 Ext'd (LBA) 54  OnTrackDM6      a5  FreeBSD         ee  EFI GPT
10  OPUS            55  EZ-Drive        a6  OpenBSD         ef  EFI (FAT-12/16/
11  Hidden FAT12    56  Golden Bow      a7  NeXTSTEP        f0  Linux/PA-RISC b
12  Compaq diagnost 5c  Priam Edisk     a8  Darwin UFS      f1  SpeedStor
14  Hidden FAT16 <3 61  SpeedStor       a9  NetBSD          f4  SpeedStor
16  Hidden FAT16    63  GNU HURD or Sys ab  Darwin boot     f2  DOS secondary
17  Hidden HPFS/NTF 64  Novell Netware  b7  BSDI fs         fd  Linux raid auto
18  AST SmartSleep  65  Novell Netware  b8  BSDI swap       fe  LANstep
1b  Hidden W95 FAT3 70  DiskSecure Mult bb  Boot Wizard hid ff  BBT
1c  Hidden W95 FAT3 75  PC/IX
Hex code (type L to list codes): <-- 8e
Changed system type of partition 1 to 8e (Linux LVM)

Command (m for help): <-- w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

Now we do the same for the hard disks /dev/sdc - /dev/sde:

fdisk /dev/sdc
fdisk /dev/sdd
fdisk /dev/sde

Then run

fdisk -l

again. The output should look like this:

server1:~# fdisk -l

Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          18      144553+  83  Linux
/dev/sda2              19        2450    19535040   83  Linux
/dev/sda4            2451        2610     1285200   82  Linux swap / Solaris

Disk /dev/sdb: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1        3040    24418768+  8e  Linux LVM

Disk /dev/sdc: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1        3040    24418768+  8e  Linux LVM

Disk /dev/sdd: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdd1               1        3040    24418768+  8e  Linux LVM

Disk /dev/sde: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sde1               1        3040    24418768+  8e  Linux LVM

Disk /dev/sdf: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdf doesn't contain a valid partition table

Now we prepare our new partitions for LVM:

pvcreate /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1

server1:~# pvcreate /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
  Physical volume "/dev/sdb1" successfully created
  Physical volume "/dev/sdc1" successfully created
  Physical volume "/dev/sdd1" successfully created
  Physical volume "/dev/sde1" successfully created

Let's revert this last action for training purposes:

pvremove /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1

server1:~# pvremove /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
  Labels on physical volume "/dev/sdb1" successfully wiped
  Labels on physical volume "/dev/sdc1" successfully wiped
  Labels on physical volume "/dev/sdd1" successfully wiped
  Labels on physical volume "/dev/sde1" successfully wiped

Then run

pvcreate /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1

again:

Now run

pvdisplay

to learn about the current state of your physical volumes:

server1:~# pvdisplay
  --- NEW Physical volume ---
  PV Name               /dev/sdb1
  VG Name
  PV Size               23.29 GB
  Allocatable           NO
  PE Size (KByte)       0
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               G8lu2L-Hij1-NVde-sOKc-OoVI-fadg-Jd1vyU

  --- NEW Physical volume ---
  PV Name               /dev/sdc1
  VG Name
  PV Size               23.29 GB
  Allocatable           NO
  PE Size (KByte)       0
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               40GJyh-IbsI-pzhn-TDRq-PQ3l-3ut0-AVSE4B

  --- NEW Physical volume ---
  PV Name               /dev/sdd1
  VG Name
  PV Size               23.29 GB
  Allocatable           NO
  PE Size (KByte)       0
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               4mU63D-4s26-uL00-r0pO-Q0hP-mvQR-2YJN5B

  --- NEW Physical volume ---
  PV Name               /dev/sde1
  VG Name
  PV Size               23.29 GB
  Allocatable           NO
  PE Size (KByte)       0
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               3upcZc-4eS2-h4r4-iBKK-gZJv-AYt3-EKdRK6

Now let's create our volume group fileserver and add /dev/sdb1 - /dev/sde1 to it:

vgcreate fileserver /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1

server1:~# vgcreate fileserver /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
Volume group "fileserver" successfully created

Let's learn about our volume groups:

vgdisplay

server1:~# vgdisplay
  --- Volume group ---
  VG Name               fileserver
  System ID
  Format                lvm2
  Metadata Areas        4
  Metadata Sequence No  1
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                0
  Open LV               0
  Max PV                0
  Cur PV                4
  Act PV                4
  VG Size               93.14 GB
  PE Size               4.00 MB
  Total PE              23844
  Alloc PE / Size       0 / 0
  Free  PE / Size       23844 / 93.14 GB
  VG UUID               3Y1WVF-BLET-QkKs-Qnrs-SZxI-wrNO-dTqhFP

Another command to learn about our volume groups:

vgscan

server1:~# vgscan
Reading all physical volumes. This may take a while...
Found volume group "fileserver" using metadata type lvm2

For training purposes let's rename our volumegroup fileserver into data:

vgrename fileserver data

server1:~# vgrename fileserver data
Volume group "fileserver" successfully renamed to "data"

Let's run vgdisplay and vgscan again to see if the volume group has been renamed:

vgdisplay

server1:~# vgdisplay
  --- Volume group ---
  VG Name               data
  System ID
  Format                lvm2
  Metadata Areas        4
  Metadata Sequence No  2
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                0
  Open LV               0
  Max PV                0
  Cur PV                4
  Act PV                4
  VG Size               93.14 GB
  PE Size               4.00 MB
  Total PE              23844
  Alloc PE / Size       0 / 0
  Free  PE / Size       23844 / 93.14 GB
  VG UUID               3Y1WVF-BLET-QkKs-Qnrs-SZxI-wrNO-dTqhFP

vgscan

server1:~# vgscan
Reading all physical volumes. This may take a while...
Found volume group "data" using metadata type lvm2

Now let's delete our volume group data:

vgremove data

server1:~# vgremove data
Volume group "data" successfully removed

vgdisplay

No output this time:

server1:~# vgdisplay

vgscan

server1:~# vgscan
Reading all physical volumes. This may take a while...

Let's create our volume group fileserver again:

vgcreate fileserver /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1

server1:~# vgcreate fileserver /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
Volume group "fileserver" successfully created

Next we create our logical volumes share (40GB), backup (5GB), and media (1GB) in the volume group fileserver. Together they use a little less than 50% of the available space (that way we can make use of RAID1 later on):

lvcreate --name share --size 40G fileserver

server1:~# lvcreate --name share --size 40G fileserver
Logical volume "share" created

lvcreate --name backup --size 5G fileserver

server1:~# lvcreate --name backup --size 5G fileserver
Logical volume "backup" created

lvcreate --name media --size 1G fileserver

server1:~# lvcreate --name media --size 1G fileserver
Logical volume "media" created

Let's get an overview of our logical volumes:

lvdisplay

server1:~# lvdisplay
  --- Logical volume ---
  LV Name                /dev/fileserver/share
  VG Name                fileserver
  LV UUID                280Mup-H9aa-sn0S-AXH3-04cP-V6p9-lfoGgJ
  LV Write Access        read/write
  LV Status              available
  # open                 0
  LV Size                40.00 GB
  Current LE             10240
  Segments               2
  Allocation             inherit
  Read ahead sectors     0
  Block device           253:0

  --- Logical volume ---
  LV Name                /dev/fileserver/backup
  VG Name                fileserver
  LV UUID                zZeuKg-Dazh-aZMC-Aa99-KUSt-J6ET-KRe0cD
  LV Write Access        read/write
  LV Status              available
  # open                 0
  LV Size                5.00 GB
  Current LE             1280
  Segments               1
  Allocation             inherit
  Read ahead sectors     0
  Block device           253:1

  --- Logical volume ---
  LV Name                /dev/fileserver/media
  VG Name                fileserver
  LV UUID                usfvrv-BC92-3pFH-2NW0-2N3e-6ERQ-4Sj7YS
  LV Write Access        read/write
  LV Status              available
  # open                 0
  LV Size                1.00 GB
  Current LE             256
  Segments               1
  Allocation             inherit
  Read ahead sectors     0
  Block device           253:2

lvscan

server1:~# lvscan
  ACTIVE            '/dev/fileserver/share' [40.00 GB] inherit
  ACTIVE            '/dev/fileserver/backup' [5.00 GB] inherit
  ACTIVE            '/dev/fileserver/media' [1.00 GB] inherit

For training purposes we rename our logical volume media into films:

lvrename fileserver media films

server1:~# lvrename fileserver media films
Renamed "media" to "films" in volume group "fileserver"

lvdisplay

server1:~# lvdisplay
  --- Logical volume ---
  LV Name                /dev/fileserver/share
  VG Name                fileserver
  LV UUID                280Mup-H9aa-sn0S-AXH3-04cP-V6p9-lfoGgJ
  LV Write Access        read/write
  LV Status              available
  # open                 0
  LV Size                40.00 GB
  Current LE             10240
  Segments               2
  Allocation             inherit
  Read ahead sectors     0
  Block device           253:0

  --- Logical volume ---
  LV Name                /dev/fileserver/backup
  VG Name                fileserver
  LV UUID                zZeuKg-Dazh-aZMC-Aa99-KUSt-J6ET-KRe0cD
  LV Write Access        read/write
  LV Status              available
  # open                 0
  LV Size                5.00 GB
  Current LE             1280
  Segments               1
  Allocation             inherit
  Read ahead sectors     0
  Block device           253:1

  --- Logical volume ---
  LV Name                /dev/fileserver/films
  VG Name                fileserver
  LV UUID                usfvrv-BC92-3pFH-2NW0-2N3e-6ERQ-4Sj7YS
  LV Write Access        read/write
  LV Status              available
  # open                 0
  LV Size                1.00 GB
  Current LE             256
  Segments               1
  Allocation             inherit
  Read ahead sectors     0
  Block device           253:2

lvscan

server1:~# lvscan
  ACTIVE            '/dev/fileserver/share' [40.00 GB] inherit
  ACTIVE            '/dev/fileserver/backup' [5.00 GB] inherit
  ACTIVE            '/dev/fileserver/films' [1.00 GB] inherit

Next let's delete the logical volume films:

lvremove /dev/fileserver/films

server1:~# lvremove /dev/fileserver/films
Do you really want to remove active logical volume "films"? [y/n]: <-- y
Logical volume "films" successfully removed

We create the logical volume media again:

lvcreate --name media --size 1G fileserver

server1:~# lvcreate --name media --size 1G fileserver
Logical volume "media" created

Now let's enlarge media from 1GB to 1.5GB:

lvextend -L1.5G /dev/fileserver/media

server1:~# lvextend -L1.5G /dev/fileserver/media
Extending logical volume media to 1.50 GB
Logical volume media successfully resized

Let's shrink it to 1GB again:

lvreduce -L1G /dev/fileserver/media

server1:~# lvreduce -L1G /dev/fileserver/media
  WARNING: Reducing active logical volume to 1.00 GB
  THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce media? [y/n]: <-- y
  Reducing logical volume media to 1.00 GB
  Logical volume media successfully resized

Until now we have three logical volumes, but we don't have any filesystems in them, and without a filesystem we can't save anything in them. Therefore we create an ext3 filesystem in share, an xfs filesystem in backup, and a reiserfs filesystem in media:

mkfs.ext3 /dev/fileserver/share

server1:~# mkfs.ext3 /dev/fileserver/share
mke2fs 1.40-WIP (14-Nov-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
5242880 inodes, 10485760 blocks
524288 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=0
320 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
        4096000, 7962624

Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 23 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.

mkfs.xfs /dev/fileserver/backup

server1:~# mkfs.xfs /dev/fileserver/backup
meta-data=/dev/fileserver/backup isize=256    agcount=8, agsize=163840 blks
         =                       sectsz=512   attr=0
data     =                       bsize=4096   blocks=1310720, imaxpct=25
         =                       sunit=0      swidth=0 blks, unwritten=1
naming   =version 2              bsize=4096
log      =internal log           bsize=4096   blocks=2560, version=1
         =                       sectsz=512   sunit=0 blks
realtime =none                   extsz=65536  blocks=0, rtextents=0

mkfs.reiserfs /dev/fileserver/media

server1:~# mkfs.reiserfs /dev/fileserver/media
mkfs.reiserfs 3.6.19 (2003 www.namesys.com)

A pair of credits:
Alexander  Lyamin  keeps our hardware  running,  and was very  generous  to our
project in many little ways.

Chris Mason wrote the journaling code for V3,  which was enormously more useful
to users than just waiting until  we could create a wandering log filesystem as
Hans would have unwisely done without him.
Jeff Mahoney optimized the bitmap  scanning code for V3,  and performed the big
endian cleanups.

Guessing about desired format.. Kernel 2.6.17-2-486 is running.
Format 3.6 with standard journal
Count of blocks on the device: 262144
Number of blocks consumed by mkreiserfs formatting process: 8219
Blocksize: 4096
Hash function used to sort names: "r5"
Journal Size 8193 blocks (first block 18)
Journal Max transaction length 1024
inode generation number: 0
UUID: 2bebf750-6e05-47b2-99b6-916fa7ea5398
ATTENTION: YOU SHOULD REBOOT AFTER FDISK!
        ALL DATA WILL BE LOST ON '/dev/fileserver/media'!
Continue (y/n):y
Initializing journal - 0%....20%....40%....60%....80%....100%
Syncing..ok

Tell your friends to use a kernel based on 2.4.18 or later, and especially not a
kernel based on 2.4.9, when you use reiserFS. Have fun.

ReiserFS is successfully created on /dev/fileserver/media.

Now we are ready to mount our logical volumes. I want to mount share in /var/share, backup in /var/backup, and media in /var/media, therefore we must create these directories first:

mkdir /var/media /var/backup /var/share

Now we can mount our logical volumes:

mount /dev/fileserver/share /var/share
mount /dev/fileserver/backup /var/backup
mount /dev/fileserver/media /var/media

Now run

df -h

You should see your logical volumes in the output:

server1:~# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              19G  665M   17G   4% /
tmpfs                  78M     0   78M   0% /lib/init/rw
udev                   10M   88K   10M   1% /dev
tmpfs                  78M     0   78M   0% /dev/shm
/dev/sda1             137M   17M  114M  13% /boot
/dev/mapper/fileserver-share
                       40G  177M   38G   1% /var/share
/dev/mapper/fileserver-backup
                      5.0G  144K  5.0G   1% /var/backup
/dev/mapper/fileserver-media
                      1.0G   33M  992M   4% /var/media

Congratulations, you've just set up your first LVM system! You can now write to and read from /var/share, /var/backup, and /var/media as usual.

We have mounted our logical volumes manually, but of course we'd like to have them mounted automatically when the system boots. Therefore we modify /etc/fstab:

mv /etc/fstab /etc/fstab_orig
cat /dev/null > /etc/fstab

vi /etc/fstab

Put the following into it:

# /etc/fstab: static file system information.

proc /proc proc defaults 0 0

/dev/sda2 / ext3 defaults,errors=remount-ro 0 1

/dev/sda1 /boot ext3 defaults 0 2

/dev/hdc /media/cdrom0 udf,iso9660 user,noauto 0 0

/dev/fd0 /media/floppy0 auto rw,user,noauto 0 0

/dev/fileserver/share /var/share ext3 rw,noatime 0 0

/dev/fileserver/backup /var/backup xfs rw,noatime 0 0

/dev/fileserver/media /var/media reiserfs rw,noatime 0 0

If you compare it to our backup of the original file, /etc/fstab_orig, you will notice that we added the lines:

/dev/fileserver/share   /var/share     ext3       rw,noatime    0 0
/dev/fileserver/backup    /var/backup      xfs        rw,noatime    0 0
/dev/fileserver/media    /var/media      reiserfs   rw,noatime    0 0

Now we reboot the system:

shutdown -r now

After the system has come up again, run

df -h

again. It should still show our logical volumes in the output:

In this chapter we will learn how to resize our logical volume share which has an ext3 filesystem. (I will show how to resize logical volumes with xfs and reiserfs filesystems further down this tutorial.)

First we must unmount it:

umount /var/share

share should not be listed anymore in the

df -h

output:

server1:~# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              19G  665M   17G   4% /
tmpfs                  78M     0   78M   0% /lib/init/rw
udev                   10M   88K   10M   1% /dev
tmpfs                  78M     0   78M   0% /dev/shm
/dev/sda1             137M   17M  114M  13% /boot
/dev/mapper/fileserver-backup
                      5.0G  144K  5.0G   1% /var/backup
/dev/mapper/fileserver-media
                      1.0G   33M  992M   4% /var/media

Now let's enlarge share from 40GB to 50GB:

lvextend -L50G /dev/fileserver/share

server1:~# lvextend -L50G /dev/fileserver/share
Extending logical volume share to 50.00 GB
Logical volume share successfully resized

Until now we have enlarged only share, but not the ext3 filesystem on share. This is what we do now:

e2fsck -f /dev/fileserver/share

server1:~# e2fsck -f /dev/fileserver/share
e2fsck 1.40-WIP (14-Nov-2006)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/fileserver/share: 11/5242880 files (9.1% non-contiguous), 209588/10485760 blocks

Make a note of the total amount of blocks (10485760) because we need it when we shrink share later on.

resize2fs /dev/fileserver/share

server1:~# resize2fs /dev/fileserver/share
resize2fs 1.40-WIP (14-Nov-2006)
Resizing the filesystem on /dev/fileserver/share to 13107200 (4k) blocks.
The filesystem on /dev/fileserver/share is now 13107200 blocks long.

Let's mount share:

mount /dev/fileserver/share /var/share

and in the

df -h

output share should now have 50GB instead of 40:

server1:~# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              19G  665M   17G   4% /
tmpfs                  78M     0   78M   0% /lib/init/rw
udev                   10M   88K   10M   1% /dev
tmpfs                  78M     0   78M   0% /dev/shm
/dev/sda1             137M   17M  114M  13% /boot
/dev/mapper/fileserver-backup
                      5.0G  144K  5.0G   1% /var/backup
/dev/mapper/fileserver-media
                      1.0G   33M  992M   4% /var/media
/dev/mapper/fileserver-share
                       50G  180M   47G   1% /var/share

Shrinking a logical volume is the other way round: first we must shrink the filesystem before we reduce the logical volume's size. Let's shrink share to 40GB again:

umount /var/share

df -h

server1:~# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              19G  665M   17G   4% /
tmpfs                  78M     0   78M   0% /lib/init/rw
udev                   10M   88K   10M   1% /dev
tmpfs                  78M     0   78M   0% /dev/shm
/dev/sda1             137M   17M  114M  13% /boot
/dev/mapper/fileserver-backup
                      5.0G  144K  5.0G   1% /var/backup
/dev/mapper/fileserver-media
                      1.0G   33M  992M   4% /var/media

e2fsck -f /dev/fileserver/share

server1:~# e2fsck -f /dev/fileserver/share
e2fsck 1.40-WIP (14-Nov-2006)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/fileserver/share: 11/6553600 files (9.1% non-contiguous), 251733/13107200 blocks

When resizing an ext3 filesystem to a certain size (instead of all available space), resize2fs takes the number of blocks as argument (you can as well specify the new size in MB, etc. See

man resize2fs

for more details). From our previous operation we know the 40GB equals 10485760 blocks so we run

resize2fs /dev/fileserver/share 10485760

server1:~# resize2fs /dev/fileserver/share 10485760
resize2fs 1.40-WIP (14-Nov-2006)
Resizing the filesystem on /dev/fileserver/share to 10485760 (4k) blocks.
The filesystem on /dev/fileserver/share is now 10485760 blocks long.

We've shrinked the filesystem, now we must shrink the logical volume, too:

lvreduce -L40G /dev/fileserver/share

server1:~# lvreduce -L40G /dev/fileserver/share
  WARNING: Reducing active logical volume to 40.00 GB
  THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce share? [y/n]: <-- y
  Reducing logical volume share to 40.00 GB
  Logical volume share successfully resized

We can ignore the warning that data might be destroyed because we have shrinked the filesystem before.

Let's mount share again:

mount /dev/fileserver/share /var/share

The output of

df -h

should now look like this:

server1:~# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              19G  665M   17G   4% /
tmpfs                  78M     0   78M   0% /lib/init/rw
udev                   10M   88K   10M   1% /dev
tmpfs                  78M     0   78M   0% /dev/shm
/dev/sda1             137M   17M  114M  13% /boot
/dev/mapper/fileserver-backup
                      5.0G  144K  5.0G   1% /var/backup
/dev/mapper/fileserver-media
                      1.0G   33M  992M   4% /var/media
/dev/mapper/fileserver-share
                       40G  177M   38G   1% /var/share

We haven't used /dev/sdf until now. We will now create the partition /dev/sdf1 (25GB) and add that to our fileserver volume group.

fdisk /dev/sdf

server1:~# fdisk /dev/sdf
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.

The number of cylinders for this disk is set to 10443.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

Command (m for help): <-- m
Command action
   a   toggle a bootable flag
   b   edit bsd disklabel
   c   toggle the dos compatibility flag
   d   delete a partition
   l   list known partition types
   m   print this menu
   n   add a new partition
   o   create a new empty DOS partition table
   p   print the partition table
   q   quit without saving changes
   s   create a new empty Sun disklabel
   t   change a partition's system id
   u   change display/entry units
   v   verify the partition table
   w   write table to disk and exit
   x   extra functionality (experts only)

Command (m for help): <-- n
Command action
   e   extended
   p   primary partition (1-4)
<-- p
Partition number (1-4): <-- 1
First cylinder (1-10443, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-10443, default 10443): <-- +25000M

Command (m for help): <-- t
Selected partition 1
Hex code (type L to list codes): <-- 8e
Changed system type of partition 1 to 8e (Linux LVM)

Command (m for help): <-- w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

Let's prepare /dev/sdf1 for LVM:

pvcreate /dev/sdf1

server1:~# pvcreate /dev/sdf1
Physical volume "/dev/sdf1" successfully created

Add /dev/sdf1 to our fileserver volume group:

vgextend fileserver /dev/sdf1

Run

vgdisplay

VG Size should now be bigger than before:

server1:~# vgdisplay
  --- Volume group ---
  VG Name               fileserver
  System ID
  Format                lvm2
  Metadata Areas        5
  Metadata Sequence No  12
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                3
  Open LV               3
  Max PV                0
  Cur PV                5
  Act PV                5
  VG Size               116.43 GB
  PE Size               4.00 MB
  Total PE              29805
  Alloc PE / Size       11776 / 46.00 GB
  Free  PE / Size       18029 / 70.43 GB
  VG UUID               iWr1Vk-7h7J-hLRL-SHbx-3p87-Rq47-L1GyEO

That's it. /dev/sdf1 has been added to the fileserver volume group.

Now let's remove /dev/sdb1. Before we do this, we must copy all data on it to /dev/sdf1:

pvmove /dev/sdb1 /dev/sdf1

This can take some minutes:

server1:~# pvmove /dev/sdb1 /dev/sdf1
  /dev/sdb1: Moved: 1.9%
  /dev/sdb1: Moved: 3.8%
  /dev/sdb1: Moved: 5.8%
  /dev/sdb1: Moved: 7.8%
  /dev/sdb1: Moved: 9.7%
  /dev/sdb1: Moved: 11.6%
  /dev/sdb1: Moved: 13.6%
  /dev/sdb1: Moved: 15.6%
  /dev/sdb1: Moved: 17.5%
  /dev/sdb1: Moved: 19.4%
  /dev/sdb1: Moved: 21.4%
  [...]
  /dev/sdb1: Moved: 85.7%
  /dev/sdb1: Moved: 87.7%
  /dev/sdb1: Moved: 89.7%
  /dev/sdb1: Moved: 91.7%
  /dev/sdb1: Moved: 93.6%
  /dev/sdb1: Moved: 95.5%
  /dev/sdb1: Moved: 97.5%
  /dev/sdb1: Moved: 99.4%
  /dev/sdb1: Moved: 100.0%

Next we remove /dev/sdb1 from the fileserver volume group:

vgreduce fileserver /dev/sdb1

server1:~# vgreduce fileserver /dev/sdb1
Removed "/dev/sdb1" from volume group "fileserver"

vgdisplay

server1:~# vgdisplay
  --- Volume group ---
  VG Name               fileserver
  System ID
  Format                lvm2
  Metadata Areas        4
  Metadata Sequence No  16
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                3
  Open LV               3
  Max PV                0
  Cur PV                4
  Act PV                4
  VG Size               93.14 GB
  PE Size               4.00 MB
  Total PE              23844
  Alloc PE / Size       11776 / 46.00 GB
  Free  PE / Size       12068 / 47.14 GB
  VG UUID               iWr1Vk-7h7J-hLRL-SHbx-3p87-Rq47-L1GyEO

Then we run

pvremove /dev/sdb1

/dev/sdb1 shouldn't be listed as a physical volume anymore:

pvdisplay

server1:~# pvdisplay
  --- Physical volume ---
  PV Name               /dev/sdc1
  VG Name               fileserver
  PV Size               23.29 GB / not usable 0
  Allocatable           yes
  PE Size (KByte)       4096
  Total PE              5961
  Free PE               1682
  Allocated PE          4279
  PV UUID               40GJyh-IbsI-pzhn-TDRq-PQ3l-3ut0-AVSE4B

  --- Physical volume ---
  PV Name               /dev/sdd1
  VG Name               fileserver
  PV Size               23.29 GB / not usable 0
  Allocatable           yes
  PE Size (KByte)       4096
  Total PE              5961
  Free PE               4681
  Allocated PE          1280
  PV UUID               4mU63D-4s26-uL00-r0pO-Q0hP-mvQR-2YJN5B

  --- Physical volume ---
  PV Name               /dev/sde1
  VG Name               fileserver
  PV Size               23.29 GB / not usable 0
  Allocatable           yes
  PE Size (KByte)       4096
  Total PE              5961
  Free PE               5705
  Allocated PE          256
  PV UUID               3upcZc-4eS2-h4r4-iBKK-gZJv-AYt3-EKdRK6

  --- Physical volume ---
  PV Name               /dev/sdf1
  VG Name               fileserver
  PV Size               23.29 GB / not usable 0
  Allocatable           yes (but full)
  PE Size (KByte)       4096
  Total PE              5961
  Free PE               0
  Allocated PE          5961
  PV UUID               1xgo2I-SBjj-0MAz-lmDu-OLZ1-3NdO-mLkS20

You could now remove /dev/sdb from the system (if this was a real system and not a virtual machine).

In this chapter we will undo all changes from the previous chapters to return to the system's original state. This is just for training purposes so that you learn how to undo an LVM setup.

First we must unmount our logical volumes:

umount /var/share
umount /var/backup
umount /var/media

df -h

server1:~# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              19G  665M   17G   4% /
tmpfs                  78M     0   78M   0% /lib/init/rw
udev                   10M   92K   10M   1% /dev
tmpfs                  78M     0   78M   0% /dev/shm
/dev/sda1             137M   17M  114M  13% /boot

Then we delete each of them:

lvremove /dev/fileserver/share

server1:~# lvremove /dev/fileserver/share
Do you really want to remove active logical volume "share"? [y/n]: <-- y
Logical volume "share" successfully removed

lvremove /dev/fileserver/backup

server1:~# lvremove /dev/fileserver/backup
Do you really want to remove active logical volume "backup"? [y/n]: <-- y
Logical volume "backup" successfully removed

lvremove /dev/fileserver/media

server1:~# lvremove /dev/fileserver/media
Do you really want to remove active logical volume "media"? [y/n]: <-- y
Logical volume "media" successfully removed

Next we remove the volume group fileserver:

vgremove fileserver

server1:~# vgremove fileserver
Volume group "fileserver" successfully removed

Finally we do this:

pvremove /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1

server1:~# pvremove  /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1
  Labels on physical volume "/dev/sdc1" successfully wiped
  Labels on physical volume "/dev/sdd1" successfully wiped
  Labels on physical volume "/dev/sde1" successfully wiped
  Labels on physical volume "/dev/sdf1" successfully wiped

vgdisplay

server1:~# vgdisplay
No volume groups found

pvdisplay

should display nothing at all:

server1:~# pvdisplay

Now we must undo our changes in /etc/fstab to avoid that the system tries to mount non-existing devices. Fortunately we have made a backup of the original file that we can copy back now:

mv /etc/fstab_orig /etc/fstab

Reboot the system:

shutdown -r now

Afterwards the output of

df -h

should look like this:

Now the system is like it was in the beginning (except that the partitions /dev/sdb1 - /dev/sdf1 still exist - you could delete them with fdisk but we don't do this now - as well as the directories /var/share, /var/backup, and /var/media which we also don't delete).

7 LVM On RAID1

In this chapter we will set up LVM again and move it to a RAID1 array to guarantee for high-availability. In the end this should look like this:

This means we will make the RAID array /dev/md0 from the partitions /dev/sdb1 + /dev/sdc1, and the RAID array /dev/md1 from the partitions /dev/sdd1 + /dev/sde1. /dev/md0 and /dev/md1 will then be the physical volumes for LVM.

Before we come to that, we set up LVM as before:

pvcreate /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
vgcreate fileserver /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
lvcreate --name share --size 40G fileserver
lvcreate --name backup --size 5G fileserver
lvcreate --name media --size 1G fileserver

mkfs.ext3 /dev/fileserver/share
mkfs.xfs /dev/fileserver/backup
mkfs.reiserfs /dev/fileserver/media

Then we mount our logical volumes:

mount /dev/fileserver/share /var/share
mount /dev/fileserver/backup /var/backup
mount /dev/fileserver/media /var/media

The output of

df -h

should now look like this:

server1:~# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              19G  666M   17G   4% /
tmpfs                  78M     0   78M   0% /lib/init/rw
udev                   10M   92K   10M   1% /dev
tmpfs                  78M     0   78M   0% /dev/shm
/dev/sda1             137M   17M  114M  13% /boot
/dev/mapper/fileserver-share
                       40G  177M   38G   1% /var/share
/dev/mapper/fileserver-backup
                      5.0G  144K  5.0G   1% /var/backup
/dev/mapper/fileserver-media
                      1.0G   33M  992M   4% /var/media

Now we must move the contents of /dev/sdc1 and /dev/sde1 (/dev/sdc1 is the second partition of our future /dev/md0, /dev/sde1 the second partition of our future /dev/md1) to the remaining partitions, because we will afterwards remove them from LVM and format them with the type fd (Linux RAID autodetect) and move them to /dev/md0 resp. /dev/md1.

modprobe dm-mirror
pvmove /dev/sdc1

vgreduce fileserver /dev/sdc1
pvremove /dev/sdc1

pvdisplay

server1:~# pvdisplay
  --- Physical volume ---
  PV Name               /dev/sdb1
  VG Name               fileserver
  PV Size               23.29 GB / not usable 0
  Allocatable           yes (but full)
  PE Size (KByte)       4096
  Total PE              5961
  Free PE               0
  Allocated PE          5961
  PV UUID               USDJyG-VDM2-r406-OjQo-h3eb-c9Mp-4nvnvu

  --- Physical volume ---
  PV Name               /dev/sdd1
  VG Name               fileserver
  PV Size               23.29 GB / not usable 0
  Allocatable           yes
  PE Size (KByte)       4096
  Total PE              5961
  Free PE               4681
  Allocated PE          1280
  PV UUID               qdEB5d-389d-O5UA-Kbwv-mn1y-74FY-4zublN

  --- Physical volume ---
  PV Name               /dev/sde1
  VG Name               fileserver
  PV Size               23.29 GB / not usable 0
  Allocatable           yes
  PE Size (KByte)       4096
  Total PE              5961
  Free PE               1426
  Allocated PE          4535
  PV UUID               4vL1e0-sr2M-awGd-qDJm-ZrC9-wuxW-2lEqp2

pvmove /dev/sde1

vgreduce fileserver /dev/sde1
pvremove /dev/sde1

pvdisplay

Now we format /dev/sdc1 with the type fd (Linux RAID autodetect):

fdisk /dev/sdc

server1:~# fdisk /dev/sdc

The number of cylinders for this disk is set to 10443.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): <-- m
Command action
   a   toggle a bootable flag
   b   edit bsd disklabel
   c   toggle the dos compatibility flag
   d   delete a partition
   l   list known partition types
   m   print this menu
   n   add a new partition
   o   create a new empty DOS partition table
   p   print the partition table
   q   quit without saving changes
   s   create a new empty Sun disklabel
   t   change a partition's system id
   u   change display/entry units
   v   verify the partition table
   w   write table to disk and exit
   x   extra functionality (experts only)

Command (m for help): <-- t
Selected partition 1
Hex code (type L to list codes): <-- L

0  Empty           1e  Hidden W95 FAT1 80  Old Minix       be  Solaris boot
1  FAT12           24  NEC DOS         81  Minix / old Lin bf  Solaris
2  XENIX root      39  Plan 9          82  Linux swap / So c1  DRDOS/sec (FAT-
3  XENIX usr       3c  PartitionMagic  83  Linux           c4  DRDOS/sec (FAT-
4  FAT16 <32M      40  Venix 80286     84  OS/2 hidden C:  c6  DRDOS/sec (FAT-
5  Extended        41  PPC PReP Boot   85  Linux extended  c7  Syrinx
6  FAT16           42  SFS             86  NTFS volume set da  Non-FS data
7  HPFS/NTFS       4d  QNX4.x          87  NTFS volume set db  CP/M / CTOS / .
8  AIX             4e  QNX4.x 2nd part 88  Linux plaintext de  Dell Utility
9  AIX bootable    4f  QNX4.x 3rd part 8e  Linux LVM       df  BootIt
a  OS/2 Boot Manag 50  OnTrack DM      93  Amoeba          e1  DOS access
b  W95 FAT32       51  OnTrack DM6 Aux 94  Amoeba BBT      e3  DOS R/O
c  W95 FAT32 (LBA) 52  CP/M            9f  BSD/OS          e4  SpeedStor
e  W95 FAT16 (LBA) 53  OnTrack DM6 Aux a0  IBM Thinkpad hi eb  BeOS fs
f  W95 Ext'd (LBA) 54  OnTrackDM6      a5  FreeBSD         ee  EFI GPT
10  OPUS            55  EZ-Drive        a6  OpenBSD         ef  EFI (FAT-12/16/
11  Hidden FAT12    56  Golden Bow      a7  NeXTSTEP        f0  Linux/PA-RISC b
12  Compaq diagnost 5c  Priam Edisk     a8  Darwin UFS      f1  SpeedStor
14  Hidden FAT16 <3 61  SpeedStor       a9  NetBSD          f4  SpeedStor
16  Hidden FAT16    63  GNU HURD or Sys ab  Darwin boot     f2  DOS secondary
17  Hidden HPFS/NTF 64  Novell Netware  b7  BSDI fs         fd  Linux raid auto
18  AST SmartSleep  65  Novell Netware  b8  BSDI swap       fe  LANstep
1b  Hidden W95 FAT3 70  DiskSecure Mult bb  Boot Wizard hid ff  BBT
1c  Hidden W95 FAT3 75  PC/IX
Hex code (type L to list codes): <-- fd
Changed system type of partition 1 to fd (Linux raid autodetect)

Command (m for help): <-- w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

Now do the same with /dev/sde1:

fdisk /dev/sde

The output of

fdisk -l

should now look like this:

server1:~# fdisk -l

Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          18      144553+  83  Linux
/dev/sda2              19        2450    19535040   83  Linux
/dev/sda4            2451        2610     1285200   82  Linux swap / Solaris

Disk /dev/sdb: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1        3040    24418768+  8e  Linux LVM

Disk /dev/sdc: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1        3040    24418768+  fd  Linux raid autodetect

Disk /dev/sdd: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdd1               1        3040    24418768+  8e  Linux LVM

Disk /dev/sde: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sde1               1        3040    24418768+  fd  Linux raid autodetect

Disk /dev/sdf: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdf1               1        3040    24418768+  8e  Linux LVM

Next we add /dev/sdc1 to /dev/md0 and /dev/sde1 to /dev/md1. Because the second nodes (/dev/sdb1 and /dev/sdd1) are not ready yet, we must specify missing in the following commands:

mdadm --create /dev/md0 --auto=yes -l 1 -n 2 /dev/sdc1 missing

server1:~# mdadm --create /dev/md0 --auto=yes -l 1 -n 2 /dev/sdc1 missing
mdadm: array /dev/md0 started.

mdadm --create /dev/md1 --auto=yes -l 1 -n 2 /dev/sde1 missing

server1:~# mdadm --create /dev/md1 --auto=yes -l 1 -n 2 /dev/sde1 missing
mdadm: array /dev/md1 started.

Afterwards we prepare /dev/md0 and /dev/md1 for LVM:

pvcreate /dev/md0 /dev/md1

server1:~# pvcreate /dev/md0 /dev/md1
Physical volume "/dev/md0" successfully created
Physical volume "/dev/md1" successfully created

and extend our fileserver volume group:

vgextend fileserver /dev/md0 /dev/md1

server1:~# vgextend fileserver /dev/md0 /dev/md1
Volume group "fileserver" successfully extended

The outputs of

Pvdisplay and vgdisplay should look like this:

server1:~# pvdisplay
  --- Physical volume ---
  PV Name               /dev/sdb1
  VG Name               fileserver
  PV Size               23.29 GB / not usable 0
  Allocatable           yes (but full)
  PE Size (KByte)       4096
  Total PE              5961
  Free PE               0
  Allocated PE          5961
  PV UUID               USDJyG-VDM2-r406-OjQo-h3eb-c9Mp-4nvnvu

  --- Physical volume ---
  PV Name               /dev/sdd1
  VG Name               fileserver
  PV Size               23.29 GB / not usable 0
  Allocatable           yes
  PE Size (KByte)       4096
  Total PE              5961
  Free PE               146
  Allocated PE          5815
  PV UUID               qdEB5d-389d-O5UA-Kbwv-mn1y-74FY-4zublN

  --- Physical volume ---
  PV Name               /dev/md0
  VG Name               fileserver
  PV Size               23.29 GB / not usable 0
  Allocatable           yes
  PE Size (KByte)       4096
  Total PE              5961
  Free PE               5961
  Allocated PE          0
  PV UUID               7JHUXF-1R2p-OjbJ-X1OT-uaeg-gWRx-H6zx3P

  --- Physical volume ---
  PV Name               /dev/md1
  VG Name               fileserver
  PV Size               23.29 GB / not usable 0
  Allocatable           yes
  PE Size (KByte)       4096
  Total PE              5961
  Free PE               5961
  Allocated PE          0
  PV UUID               pwQ5AJ-RwVK-EebA-0Z13-d27d-2IdP-HqT5RW

server1:~# vgdisplay
  --- Volume group ---
  VG Name               fileserver
  System ID
  Format                lvm2
  Metadata Areas        4
  Metadata Sequence No  14
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                3
  Open LV               3
  Max PV                0
  Cur PV                4
  Act PV                4
  VG Size               93.14 GB
  PE Size               4.00 MB
  Total PE              23844
  Alloc PE / Size       11776 / 46.00 GB
  Free  PE / Size       12068 / 47.14 GB
  VG UUID               dQDEHT-kNHf-UjRm-rmJ3-OUYx-9G1t-aVskI1

Now we move the contents of /dev/sdb1 to /dev/md0 and the contents of /dev/sdd1 to /dev/md1, then we remove /dev/sdb1 and /dev/sdd1 from LVM:

pvmove /dev/sdb1 /dev/md0

pvmove /dev/sdd1 /dev/md1

vgreduce fileserver /dev/sdb1 /dev/sdd1
pvremove /dev/sdb1 /dev/sdd1

Now only /dev/md0 and /dev/md1 should be left as physical volumes:

pvdisplay

server1:~# pvdisplay
  --- Physical volume ---
  PV Name               /dev/md0
  VG Name               fileserver
  PV Size               23.29 GB / not usable 0
  Allocatable           yes (but full)
  PE Size (KByte)       4096
  Total PE              5961
  Free PE               0
  Allocated PE          5961
  PV UUID               7JHUXF-1R2p-OjbJ-X1OT-uaeg-gWRx-H6zx3P

  --- Physical volume ---
  PV Name               /dev/md1
  VG Name               fileserver
  PV Size               23.29 GB / not usable 0
  Allocatable           yes
  PE Size (KByte)       4096
  Total PE              5961
  Free PE               146
  Allocated PE          5815
  PV UUID               pwQ5AJ-RwVK-EebA-0Z13-d27d-2IdP-HqT5RW

Now we format /dev/sdb1 with fd (Linux RAID autodetect):

fdisk /dev/sdb

server1:~# fdisk /dev/sdb

The number of cylinders for this disk is set to 32635.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): <-- m
Command action
   a   toggle a bootable flag
   b   edit bsd disklabel
   c   toggle the dos compatibility flag
   d   delete a partition
   l   list known partition types
   m   print this menu
   n   add a new partition
   o   create a new empty DOS partition table
   p   print the partition table
   q   quit without saving changes
   s   create a new empty Sun disklabel
   t   change a partition's system id
   u   change display/entry units
   v   verify the partition table
   w   write table to disk and exit
   x   extra functionality (experts only)

Command (m for help): <-- t
Selected partition 1
Hex code (type L to list codes): <-- fd
Changed system type of partition 1 to fd (Linux raid autodetect)

Command (m for help): <-- w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

Do the same with /dev/sdd1:

fdisk /dev/sdd

Next add /dev/sdb1 to /dev/md0 and /dev/sdd1 to /dev/md1:

mdadm --manage /dev/md0 --add /dev/sdb1

server1:~# mdadm --manage /dev/md0 --add /dev/sdb1
mdadm: added /dev/sdb1

mdadm --manage /dev/md1 --add /dev/sdd1

server1:~# mdadm --manage /dev/md1 --add /dev/sdd1
mdadm: added /dev/sdd1

Now the two RAID arrays will be synchronized. This will take some time, you can check with

cat /proc/mdstat

when the process is finished. The output looks like this for an unfinished process:

server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md1 : active raid1 sdd1[2] sde1[0]
      24418688 blocks [2/1] [U_]
      [=>...................]  recovery =  6.4% (1586560/24418688) finish=1.9min speed=198320K/sec

md0 : active raid1 sdb1[2] sdc1[0]
      24418688 blocks [2/1] [U_]
      [==>..................]  recovery = 10.5% (2587264/24418688) finish=2.8min speed=129363K/sec

unused devices:

and like this when the process is finished:

server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md1 : active raid1 sdd1[1] sde1[0]
24418688 blocks [2/2] [UU]

md0 : active raid1 sdb1[1] sdc1[0]
24418688 blocks [2/2] [UU]

unused devices:

If you have a look at PV Size in the output of

pvdisplay

you will see that 2 * 23.29GB = 46.58GB are available, however only 40GB (share) + 5GB (backup) + 1GB (media) = 46GB are used which means we could extend one of our logical devices with about 0.5GB. I've already shown how to extend an ext3 logical volume (share), so we will resize media now which uses reiserfs. reiserfs filesystems can be resized without unmounting:

lvextend -L1.5G /dev/fileserver/media

server1:~# lvextend -L1.5G /dev/fileserver/media
Extending logical volume media to 1.50 GB
Logical volume media successfully resized

resize_reiserfs /dev/fileserver/media

server1:~# resize_reiserfs /dev/fileserver/media
resize_reiserfs 3.6.19 (2003 www.namesys.com)

resize_reiserfs: On-line resizing finished successfully.

The output of

df -h

looks like this:

If we want our logical volumes to be mounted automatically at boot time, we must modify /etc/fstab again (like in chapter 3):

mv /etc/fstab /etc/fstab_orig
cat /dev/null > /etc/fstab

vi /etc/fstab

DN(as)S

2010-08-14T16:21:00.000-07:00

A = Address record, A records are used to map an IP address to a hostname or subdomain.Usally automatically created

CNAME = Canonical name, a CNAME record refereces another record, effectivley making it an alias, normaly used to map a subdomain to an existing domain.

MX = Mail exchanger, an MX record specifies a mail server for the domain, normaly more than one will be specified and they will be given a priority to denote which server to try first (for backup mail servers etc)

NS = Name server, an NS record lists the DNS servers responsible for the domain, again more than one can and normaly is provided so if the primary server fails a backup can be used.

PTR = Pointer, a PTR record is used to resolve an ip address to a name, PTR records are what make reverse lookups work.

SOA = Start of authority, a SOA record contains a lot of the basic information about the domain relating to how updates should be handled, primary name server and contact detail.

- = SOA record = -
-------------------
@ IN SOA ns0.example.com. hostmaster.example.com. (
2005081701 ; Serial
10800 ; Refresh
3600 ; Retry
3600000 ; Expire
86400 ) ; Minimum

- = MX Record2 = -
-------------------
MX 5 mx1.example.com.
MX 5 mx2.example.com.

- = NS Records = -
------------------
IN NS ns0.example.com.
IN NS ns1.example.com.

- = A Records = -
----------------
@ IN A 9.8.7.6
cvs IN A 8.8.8.8

These effectivley map example.com to 9.8.7.6 and cvs.example.com to 8.8.8.8.

It's worth noting this a record is special since the "@" means all destinations not setup in the zone file for this domain goto this, this is effectivley the "base" level of the dns.

- = CNAME Record = -
----------------------
www IN CNAME example.com.

This maps the www subdomain (yes, it is actualy a subdomain :O) to example.com, any changes made to the record for example.com automaticly filter back to www, www.example.com will go to 9.9.9.9, subdomains can basicly be pointed anywhere you want to point them

I've not listed a PTR record in this zone file because well, it wouldnt go in one, the PTR records would go into a zone file for the IP range as oppsed to the hostname, such a file would be named 777.888.999.in-addr.arpa and the PRT records would be specified using the last octet.

So for example.com we'd have a PTR record like this

6 IN PTR example.com.

lets bartend : something about drinks

2010-05-08T15:30:00.001-07:00

under construction ... coming soon

lets bartend : types of glass

2010-05-08T14:34:00.001-07:00

Brandy Snifter
They have a very short stem to be placed between the middle and ring finger, to allow the palm to heat the spirit while holding.
Size: 5 to 25 ounces

Cocktail Glass
Also known as a martini glass. The shape of the glass helps keep ingredients from separating, and the stem allows the drink to stay cool while holding.
Size: 4 to 6 ounces

Collins Glass
Named after the drink Tom Collins, this glass is tall and skinny and can be found in clear of frosted glass.
Size: 10 to 16 ounces.

Cordial Glass
Small and stemmed glass used for serving small portions of liquors at times such as after a meal.
Size: Approximately 2 ounce

Champagne Flute
These are tall, slender dainty glasses. The flute helps preserve the carbonation of champagne, while the stem helps keep it chilled.
Size: 7 to 10 ounces

Highball Glass
The base of this glass is the same diameter as the rim, creating a tall, straight, wide glass.
Size: Approximately 12 ounces

Hurricane Glass
This tall and elegantly shaped glass was named after it's hurricane-lamp-like shape and used for exotic or tropical drinks.
Size: Approximately 15 ounce

Irish Coffee Cup
With a short stem and a handle, this glass is also known as the Irish Coffee Glass. It is used for almost any hot beverage.
Size: Approximately 8 to 10 ounces

Margarita-Coupette Glass
This slightly larger and rounded approach to a cocktail glass has a broad-rim for holding salt, ideal for margarita's. It is also used in daiquiris and other fruit drinks.
Size: Approximately 12 ounces

Mason Jar
This large square containers are effective in keeping their contents sealed in an air tight environment.
Size: Approximately 16 ounces

Beer Mug
Usually made of thick glass, quite heavy, with a large handle, it's the traditional beer container.
Size: Approximately 16 ounces

Parfait Glass
Pronounced Par fey is also known as the glass for foo foo drinks. This glass comes in various shapes. The stem keeps the ice cream from melting quickly.
Size: Approximately 12 ounces

Beer Pilsner
This glass is often used to serve beer and beer-related mixed drinks
Size: 12-20 ounces

Pint Glass
This glass is often used to serve a pint of beer and beer-related mixed drinks Size: 1 pin

Pitcher
This larger container usually has a handle and a lip or spout for pouring the contents into several glasses. Available in glass or plastic.
Size: Approximately 30 to 60 ounces

Pousse Cafe Glass
Traditionally a sort of narrow, tall cordial glass often to contain a slightly greater volume of liquid than a standard 1 ounce cordial. The Pousse Cafe and its variations were liqueur drinks poured in layers so the heaviest liqueur or syrup would settle in the bottom and progressively lighter (lower specific gravity) liqueurs or spirits would float atop one another creating a layered effect. Pousse Cafes are meant to be sipped one layer at a time.

Size: 1.5 ounces

Red Wine Glass
This elegantly shaped stemmed glass is generally used to serve red wine. The stem is used for holding not to affect the temperature of the drink.
Size: Approximately 8 to 10 ounces.

Punch Bowl
A large semispherical bowl suitable for punches or large mixes. Often used at parties.
Size: Approximately 1 to 5 gallons

Sherry Glass
This small narrow stemmed glass is the choice for aperitifs, ports, and sherry.
Size: Approximately 2 ounces

Rock Glass
The base diameter of this short glass is the same size as the rim.
Size: 4 to 8 ounces

Shot Glass
Usually made of very thick glass, especially at the bottom. They come in two types. The regular shot glass is approximately 2 inches tall and the tall shot glasses can be as high as 6 inches. Normally they both have the same diameter. The regular shot glass is also used as a measuring tool when preparing cocktails.
Short Size: Approximately 1 to 2 ounces
Tall Size: Approximately 2 to 6 ounces

White Wine Glass
The stem helps keep the wine stay chilled by not allowing the heat of the hand to be in contact with the part of the glass that actually holds the wine.
Size: Approximately 6 to 8 ounces

Whiskey Sour Glass
This is a stemmed, wide opening glass, alike to a small version of a champagne flute. Size: Approximately 5 ounces

my firsts jack and coke

2010-05-08T13:50:00.000-07:00

" I don`t drink to get drunk but I drink to act drunk "

I was 16 when for the first time I got to try Jack and Coke , I still remember that day , It was stolen from the fridge the coke I mean and borrowed Jack from my dad`s bar . I slowly poured coke in the glass it was frizzy and cold ... it looked so beautiful in that rocks glass , water droplets on its surface and a frizzy soda inside it OMG ... I fell in love with that drink and then hastily I added some jack without any previous first hand experience but I was an Vicarious expert , learned by watching and listening so what if I never got a chance to make pegs for the gentleman .

That was my first step towards adulthood .Jack and Coke in my hand pink Floyd in the background , it was them because my dad use to listen to them but I liked MJ and blue though but I thought Floyd would be a better choice as that is what grown ups listen to . But anyways It took me like an hour to get to the couch with the glass in my hand , I also wanted to lit the cigar but that would have been too much as i just had 3 hours of no parents or should I say of being an adult or a man in the house.

I sat on the couch about to sip in the ambrosia I just had brewed . And the door bell rings . OK , so I thought have kept the coke back in fridge and have diluted jack by adding little water to it , come on I cannot stand my father discombobulated by the diminishing jack so just for him I added a little water , right then I am good . My parents were off to some relatives place a family function ( baby shower as far as I remember ) , so it couldnt be my parents then who the fuck ... with a frown I opened the door and SURPRISE .... its my dad , wow amazing I love murphy . he rushed in to grab something and just before leaving he saw that glass and asked wasszat . "I dont know" , "what ?? lemme c that " . " how am I suppose to know everything that is lying around , I was in my room studying , I got my exams next week "
"I don`t know what were you upto but if you were studying why is the music on and lemme c that whats in that glass ."
OMG I so wanted to run from that place . "OH our neighborhood is so noisy i get distracted so I turned it on atlest will keep away the stupid noise but I was studyng math differential calculus , its so awesome i like so much , I love math." Well I dunno y I said that but I suck at math i failed the last test was planning to drop it . Anyways He helped himself grabbed the glass , its still cold its just made and its JACK ,

REST is history

well a few days after a lock was placed on the bar and I majored in math .

that was my first encounter with a cocktail . Was Awesome not the experience but the cocktail and I became a fan of it . Since then I have been into cocktails I wanted to be a bartender but I am not that talented so became an engineer.

But I still love to talk about bars and attending people in bars .

Learn them .. MS RUN commands

2010-05-08T12:30:00.001-07:00

Windows XP Run Command List
1. Accessibility Controls – access.cpl
2. Accessibility Wizard – accwiz
3. Add Hardware – Wizardhdwwiz.cpl
4. Add/Remove Programs – appwiz.cpl
5. Administrative Tools control – admintools
6. Automatic Updates – wuaucpl.cpl
7. Bluetooth Transfer Wizard – fsquirt
8. Calculator – calc
9. Certificate Manager – certmgr.msc
10. Character Map – charmap
11. Check Disk Utility – chkdsk
12. Clipboard Viewer – clipbrd
13. Command Prompt – cmd
14. Component Services – dcomcnfg
15. Computer Management – compmgmt.msc
16. Control Panel – control
17. Date and Time Properties – timedate.cpl
18. DDE Shares – ddeshare
19. Device Manager – devmgmt.msc
20. Direct X Control Panel (If Installed)- directx.cpl
21. Direct X Troubleshooter- dxdiag
22. Disk Cleanup Utility- cleanmgr
23. Disk Defragment- dfrg.msc
24. Disk Management- diskmgmt.msc
25. Disk Partition Manager- diskpart
26. Display Properties (w/Appearance Tab Preselected)- control color
27. Display Properties- control desktop
28. Display Properties- desk.cpl
29. Dr. Watson System Troubleshooting Utility- drwtsn32
30. Driver Verifier Utility- verifier
31. Event Viewer- eventvwr.msc
32. File Signature Verification Tool- sigverif
33. Files and Settings Transfer Tool- migwiz
34. Findfast- findfast.cpl
35. Firefox (if installed)- firefox
36. Folders Properties- control folders
37. Fonts- control fonts
38. Fonts Folder- fonts
39. Free Cell Card Game- freecell
40. Game Controllers- joy.cpl
41. Group Policy Editor (XP Prof)- gpedit.msc
42. Hearts Card Game- mshearts
43. Help and Support- helpctr
44. HyperTerminal- hypertrm
45. Iexpress Wizard- iexpress
46. Indexing Service- ciadv.msc
47. Internet Connection Wizard- icwconn1
48. Internet Explorer- iexplore
49. Internet Properties- inetcpl.cpl
50. Internet Setup Wizard- inetwiz
51. IP Configuration (Delete DNS Cache Contents)- ipconfig /flushdns
52. IP Configuration (Display Connection Configuration) – ipconfi/all
53. IP Configuration (Display DHCP Class ID)- ipconfig/showclassid
54. IP Configuration (Display DNS Cache Contents)- ipconfig /displaydns
55. IP Configuration (Modifies DHCP Class ID)- ipconfig /setclassid
56. IP Configuration (Release All Connections)- ipconfig /release
57. IP Configuration (Renew All Connections)- ipconfig /renew
58. IP Configuration(RefreshesDHCP&Re-RegistersDNS)-ipconfig/registerdns
59. Java Control Panel (If Installed)- javaws
60. Java Control Panel (If Installed)- jpicpl32.cpl
61. Keyboard Properties – control keyboard
62. Local Security Settings – secpol.msc
63. Local Users and Groups – lusrmgr.msc
64. Logs You Out Of Windows – logoff…..
65. Malicious Software Removal Tool – mrt
66. Microsoft Access (if installed) – access.cpl
67. Microsoft Chat – winchat
68. Microsoft Excel (if installed) – excel
69. Microsoft Frontpage (if installed)- frontpg
70. Microsoft Movie Maker – moviemk
71. Microsoft Paint – mspaint
72. Microsoft Powerpoint (if installed)- powerpnt
73. Microsoft Syncronization Tool – mobsync
74. Microsoft Word (if installed)- winword
75. Minesweeper Game – winmine
76. Mouse Properties – control mouse
77. Mouse Properties – main.cpl
78. Nero (if installed)- nero
79. Netmeeting – conf
80. Network Connections – control netconnections
81. Network Connections – ncpa.cpl
82. Network Setup Wizard – netsetup.cpl
83. Notepad – notepad
84. Nview Desktop Manager (If Installed)- nvtuicpl.cpl
85. Object Packager – packager
86. ODBC Data Source Administrator- odbccp32.cpl
87. On Screen Keyboard – osk
88. Opens AC3 Filter (If Installed) – ac3filter.cpl
89. Outlook Express – msimn
90. Paint – pbrush
91. Password Properties – password.cpl
92. Performance Monitor – perfmon.msc
93. Phone and Modem Options – telephon.cpl
94. Phone Dialer – dialer
95. Pinball Game – pinball
96. Power Configuration – powercfg.cpl
97. printers and Faxes – control printers
98. Printers Folder – printers
99. Private Character Editor – eudcedit
100. Quicktime (If Installed)- QuickTime.cpl
101. Real Player (if installed)- realplay
102. Regional Settings – intl.cpl
103. Registry Editor – regedit
104. Registry Editor – regedit32
105. Remote Access Phonebook – rasphone
106. Remote Desktop – mstsc
107. Removable Storage – ntmsmgr.msc
108. Removable Storage Operator Requests – ntmsoprq.msc
109. Resultant Set of Policy (XP Prof) – rsop.msc
110. Scanners and Cameras – sticpl.cpl
111. Scheduled Tasks – control schedtasks
112. Security Center – wscui.cpl
113. Services – services.msc
114. Shared Folders – fsmgmt.msc
115. Shuts Down Windows – shutdown
116. Sounds and Audio – mmsys.cpl
117. Spider Solitare Card Game – spider
118. SQL Client Configuration – cliconfg
119. System Configuration Editor – sysedit
120. System Configuration Utility – msconfig
121. System File Checker Utility (Purge File Cache)- sfc /purgecache
122. System File Checker Utility (Return to Default Setting)- sfc /revert
123. System File Checker Utility (Scan Immediately)- sfc /scannow
124. System File Checker Utility (Scan On Every Boot) – sfc /scanboot
125. System File Checker Utility (Scan Once At Next Boot)- sfc /scanonce
126. System File Checker Utility (Set Cache Size to size x)-sfc/cachesize=x
127. System Information – msinfo32.
128. System Properties – sysdm.cpl
129. Task Manager – taskmgr
130. Task Manager – taskmgr
131. TCP Tester – tcptest
132. Telnet Client – telnet
133. Tweak UI (if installed) – tweakui
134. User Account Management- nusrmgr.cpl
135. Utility Manager – utilman
136. Windows Address Book – wab
137. Windows Address Book Import Utility – wabmig
138. Windows Backup Utility (if installed)- ntbackup
139. Windows Explorer – explorer
140. Windows Firewall- firewall.cpl
141. Windows Magnifier- magnify
142. Windows Management Infrastructure – wmimgmt.msc
143. Windows Media Player – wmplayer
144. Windows Messenger – msmsgs
145. Windows Picture Import Wizard (need camera connected)- wiaacmgr
146. Windows System Security Tool – syskey
147. Windows Update Launches – wupdmgr
148. Windows Version (to show which version of windows)- winver
149. Windows XP Tour Wizard – tourstart
150. Wordpad – write
151. Adobe Acrobat (if installed) – acrobat
152. Adobe Designer (if installed)- acrodist
153. Adobe Distiller (if installed)- acrodist
154. Adobe ImageReady (if installed)- imageready
155. Adobe Photoshop (if installed)- photoshop

SHOW command cisco

2010-05-08T12:19:00.000-07:00

SHOW COMMANDS

· Show access-lists - all access lists on the router

· Show cdp - cdp timer and holdtime frequency

· Show cdp entry * - same as next

· Show cdp neighbors detail - details of neighbor with ip add and ios version

· Show cdp neighbors - id, local interface, holdtime, capability, platform portid

· Show cdp interface - int’s running cdp and their encapsulation

· Show cdp traffic - cdp packets sent and received

· Show controllers serial 0 - DTE or DCE status

· Show dialer - number of times dialer string has been reached, other stats

· Show flash - files in flash

· Show frame-relay lmi - lmi stats

· Show frame-relay map - static and dynamic maps for PVC’s

· Show frame-relay pvc - pvc’s and dlci’s

· Show history - commands entered

· Show hosts - contents of host table

· Show int f0/26 - stats of f0/26

· Show interface Ethernet 0 - show stats of Ethernet 0

· Show ip - ip config of switch

· Show ip access-lists - ip access-lists on switch

· Show ip interface - ip config of interface

· Show ip protocols - routing protocols and timers

· Show ip route - Displays IP routing table

· Show ipx access-lists - same, only ipx

· Show ipx interfaces - RIP and SAP info being sent and received, IPX addresses

· Show ipx route - ipx routes in the table

· Show ipx servers - SAP table

· Show ipx traffic - RIP and SAP info

· Show isdn active - number with active status

· Show isdn status - shows if SPIDs are valid, if connected

· Show mac-address-table - contents of the dynamic table

· Show protocols - routed protocols and net_addresses of interfaces

· Show running-config - dram config file

· Show sessions - connections via telnet to remote device

· Show startup-config - nvram config file

· Show terminal - shows history size

· Show trunk a/b - trunk stat of port 26/27

· Show version - ios info, uptime, address of switch

· Show vlan - all configured vlan’s

· Show vlan-membership - vlan assignments

· Show vtp - vtp configs

2010-05-08T12:16:00.000-07:00

lets talk about cisco switch fundamentals :

Adding an IP to the switch and not wasting a port .
_______________________________________
                        enable
                        conf term
                        int vlan1
                        ip addre 10.196.205.5 255.255.255.255
                        no shutdown
                        exit
                        ip default gateway 10.196.205.1
____________exit ______________________________

Removing an IP from a switch
enable
conf ter
int vlan 1
no ip addr
exit

configuring Interfaces and ports
enable
conf ter
int f0/0
duplex full ( also can be auto , half )
speed auto
spanning-tree portfast (use this only if connected to a server or workstation , it disables spanning tree protocol )

and one can also use

int range f0/0-10 for configuring multiple ports at a time .

one can also use the following shell script

> i=1;while [ $i -lt 25 ]; do echo "int fast0/$i"; echo speed auto; echo duplex auto; echo span portfast; let i+=1; done;

Blogger Buzz: Blogger integrates with Amazon Associates

2010-05-08T12:01:00.000-07:00

Blogger Buzz: Blogger integrates with Amazon Associates

DAG ...

2010-04-24T22:39:00.000-07:00

finally today I got a chance to configure DAG exchange 2010 on a live environment , nailed it . Though was on the call with microsoft for over 2 hrs but it was easy , it was just we being too chary , as we had no window for errors as running late already and the management is a little pissed ... but whatever it was good.

a good detailed explanation tomorrow.

2010-04-17T16:30:00.000-07:00

Disaster Recovery is the buzz word . It was real costly and had lotta overheads till ystrday but now whatever softwares are being roll out DR is considered a core requirement . Same applies to exchange 2010 , apart from being more efficient and having like a million new gems it has also got a DR option . Well I am in a team and will be working on it soon . so I will keep all posted.

prerequisites : need to know somethin about what all has happned.

changing the logon screen .

2010-04-17T16:22:00.001-07:00

i was asked to change the logon screen i had no clue how to do it ... change the logon screen on Terminal Server , tat sounded easy but with the limited permissions I had it got so difficult .

well just have to remember that change the file in system32\oobe\info\backgrounds
add a file backgroundDefaul.jpeg... and yes it should be a jpeg file less than 256k ...
quiet possible that info\background might not exist so go ahead create one ...and dont fear changing the background.bmp file .

if not then also change the following registry entry

hklm\software\microsoft\window\currentversion\authentication\logonUI\Background

and change the OEMbackground to 0 ...

2010-04-17T16:19:00.000-07:00

have been out of touch for quiet some time but m back with a bang .. actually to bang my head .. now onwards the blogs would not be about me but the type of technologies I workon ..... so here we go .... hit it ..

oh .. and so that you kno we will mostly be talking about Vmware , MS servers and switches .

2009-04-17T15:29:00.000-07:00

wooh .. i feeel so low today ... i dont feel like studyn . I took a day off from the schoool . I wasted the whole day in front fo mah laptop tryin to read a book on distributed computing but it was of no use ...i just wandered from sites to sites , looking for nothing . And the best part was i after 10 min was given mah self an ulitmatum .. tat .. bastard u`ll start studyn in 10 min ... m givin you 10 min to pack up and then u gonna get back to your books . but it s 630 now and i am fellin hungry .. `ill eat and then after 10 min i`ll start studyn.

2009-04-09T16:32:00.000-07:00

wow wow wow ... I got a fuckin call .. who says the US economy is ailing ... By the way which wine would you prefer sweetheart .. how` bout pointe noire .. yeah .... lemme treat you ..

how exicited was I .. My first final calll for a job ... wen everyone else is struggling to get even a call for internship ...i made it to a job .... I cracked it it the very first attempt .. jeeeesss ... i rock.... Juss one more step to bloomberg ... YOOOO victory ... first job with Bloomberg .. yeah .. baby ... sounds so good. ..

had an assignment due the next day .. fuck it I dont give it a shit man ... dont wanna submit .

i was in my own world ... the day arrived ... suite up dude .. lookin cool ... dress to killl ... diint kno i gonna die ...

At 2 was at the lounge .. i was lookin soo ssoo confident as if i was the interviewer not the interviewee ....

" Rachit ... pls come in ..."
"oh ..hi ... how are u .. miss .... i mean Cindy .... " and inside I was ... gal dont fall for me ...m a born cassanovvaa ...now i can see how stupid it must have been ...

any went in ... grabbed the chair and I made a handshake move ... askin how u doin.....
with a sly smile and a firm shake ... as if I was signaling that guy ...dude get ready to get bamboozeeled by my esoteric answers ...

Hmmmm..... your resume sounds pretty impressive .eeh ..mm Racheet ....

did I pronouce it right ...

with a air of superiority , a haughty smile , dead man`s expression and acquiescing gesture (shaking head ) i said " ehh...dontya worry it`s fine .. btw it raCHIT and ya thank u "

hmmm.... ur credentials look impressive ... SO u kno a lot about networking it seems ....
temme smoethn about socks ...

oh .. SOCKS is an Internet protocol designed to allow clients to communicate with proxy servers or VPN servers through network firewalls.

good ... have u heard about dot11 arp-cache..

a wad ....

I mean DOT 11ARP_CACHE

ehhh... address resolution cache ...

ha ha ha it seems u are good with networking . .

can u Prove tat for a CIOQ switch a speed up of 2 is enough for 100 throughput ...

ehh h... well i kno I how a CIOQ works and also have ...

OOK ... so u have got a good experience with BGP it seems ..
so have u ever worked with it ....

ehh...no but ... I ha..

OOKKK ... so u kno snort tooo ...

yea a li

hmm.. can u tell me about abd and and and and ... and also ...
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he went on aand on and on ..... after 15 min of this mind boggling sessin ..i looked at my watch
thinkin muss be an hour or so ... but it wrer juss 15 min ... JEESUUUSS

i was perspiring , stammering , fretting , forgettin and a lotta other things ... i was not even able to hear him in one go ... My Adam`s apple was jumpin so fukin frequently ... tat it seemd like a bouncing ball ...
A torture ... and it got worse wid time ....

but I bounced back ...

after like 30 mins of inslut ... i got used to it ... i was smiling like a sage and laughin on every questioin asked and this made him nervous .. he must hav thought i was on the verge of goin crazy .... ha ha ah ... he stopped the shower of his trident , that were like hittin me inthe heels me being achilles ... lol .... , and now he came down to some stuupid qustions ... HR kindda .. so racheeet ... seems u are good on field too ...

"No ... I am actually good at no sport .. "

OOk ...so u like to read ...

a big smile ... I hate book ...

oo..I dont like them either ..

so wad are your long term plans ...

i wanna be a philosopher ...

A big smile on his face ... you kno wad ... we think alike ...

so any quesions ...

no ... thnk u ... goood day ...

wid a wry smile i left like a winner .. who lost everything ... but gainded alll ....

REsults :

Soory to inform u tat u donot fit into our requirement ....

luck for your future ....

shatterd all my dreams ... and I was bak to normalll ....

time to sleep ... i guess ... havnt slept for like 40 hours ...

goin for a interview ... LUCKKKK