Blissless Immersion

Virtualbox an Esxi5.0 Abstraction layer

2011-09-20T23:32:00.000-07:00

So last night I installed Esxi5.0 "freeware" in virtualbox. Its pretty straight forward, and I mean just install from iso but there are a few "non-issues". Esxi5.0 has to be installed on something that is at minimum a dual core, and you have to devote both CPU's to virtualbox. If installed on an AMD Phenom its crying about not having the virtualization bit enabled on my cpu. Boo hoo. ;)

Centos5: Pear + memcache

2011-09-17T15:27:00.000-07:00

Go ahead and install pear from the instructions here:

http://pear.php.net/manual/en/installation.getting.php

Its as simple as wget'ing the file of interest and then using it. After the "brief" installer, and I mean brief.


#> pecl install memcache

Note: I had to use kind of a PHP hack to get this working. ITs listed here: http://blog.mostlychris.com/2009/07/fatal-error-allowed-memory-size-of-8388608-bytes-exhausted-pear/ .

It resolves a issue with a script running out of memory before the install completes.

Last but not least since this is a a Centos5 system you'll need to do the following:


echo "extension=memcache.so" > /etc/php.d/memcached.ini

Creating a RPM for Memcached is stupidly simple

2011-09-13T04:19:00.001-07:00

Here we go!

Post is here: http://code.google.com/p/memcached/wiki/NewInstallFromSource

The short and sweet of it is:

echo "%_topdir /home/melinko2003/rpmbuild" >> ~/.rpmmacros
mkdir -p /home/melinko2003/rpmbuild/{SPECS,BUILD,SRPMS,RPMS,SOURCES}
wget http://memcached.org/latest
rpmbuild -ta memcached-1.x.x.tar.gz

PHP4 X86_64 on Centos5 + Amendment.

2011-03-24T01:50:00.001-07:00

In my previous blog I solved a headache, just remember do not yum install mysql-devel, use the rpm.

http://melinko2003.blogspot.com/2011/03/php4-x8664-on-centos5.html

PHP4 X86_64 on Centos5

2011-03-24T01:44:00.000-07:00

After some Hardcore testing, I finally figured it out :D Kids we now have 4.4.9 x86_64. Here are the modifications I had to make to get it to compile correctly! WOOHOO!

wget http://downloads.mysql.com/archives/mysql-5.0/MySQL-devel-community-5.0.45-0.rhel5.i386.rpm

rpm --oldpackage --force -Uvh MySQL-devel-community-5.0.45-0.rhel5.i386.rpm

[root@localhost SPECS]# diff php4-4.4.9_melinko.spec php4-4.4.8_LAB8.spec
8,9c8,9
< Version: 4.4.9
< Release: melinko%{?dist}
---
> Version: 4.4.8
> Release: LAB8%{?dist}
556c556
< --with-mysql=shared \
---
> --with-mysql=shared,%{_prefix} \
573,574c573,574
< --with-mime-magic=/usr/lib/rpm/magic.mime \
< $* || tail config.log
---
> --with-mime-magic=%{_libdir}/rpm/magic.mime \
> $* || tail -300 config.log
586c586
< build --with-apxs2=/usr/sbin/apxs
---
> build --with-apxs2=%{_sbindir}/apxs

PHP4 on Centos 5

2011-03-23T01:03:00.000-07:00

So I found this tonight, bad news it only works on i386 - i868, sorry folks no x86_64 :(

I will provide credit, where it is due -> http://www.labcoding.com

#> sudo yum install rpm-build autoconf automake m4 gcc gcc-c++ bison flex
#> sudo yum install bzip2-devel curl-devel db4-devel expat-devel gmp-devel aspell-devel httpd-devel libjpeg-devel libpng-devel pam-devel openssl-devel zlib-devel pcre-devel krb5-devel libc-client-devel cyrus-sascl-devel openldap-devel mysql-devel postgresql-devel unixODBC-devel net-snmp-devel elfutils-devel libxslt-devel libxml2-devel ncurses-devel freetype-devel
#> sudo yum install aspell-devel libtool libxslt-devel

#> wget http://www.labcoding.com/yum/centos/5/i386/SRPMS/php4-4.4.8-LAB8.src.rpm
#> cd /usr/src/redhat/SPECS
#> rpmbuild -bb php4-4.4.8_LAB8.spec


Checking for unpackaged file(s): /usr/lib/rpm/check-files /var/tmp/php4-root
Wrote: /usr/src/redhat/RPMS/i386/php4-4.4.8-LAB8.i386.rpm
Wrote: /usr/src/redhat/RPMS/i386/php4-devel-4.4.8-LAB8.i386.rpm
Wrote: /usr/src/redhat/RPMS/i386/php4-pear-4.4.8-LAB8.i386.rpm
Wrote: /usr/src/redhat/RPMS/i386/php4-imap-4.4.8-LAB8.i386.rpm
Wrote: /usr/src/redhat/RPMS/i386/php4-ldap-4.4.8-LAB8.i386.rpm
Wrote: /usr/src/redhat/RPMS/i386/php4-mysql-4.4.8-LAB8.i386.rpm
Wrote: /usr/src/redhat/RPMS/i386/php4-pgsql-4.4.8-LAB8.i386.rpm
Wrote: /usr/src/redhat/RPMS/i386/php4-odbc-4.4.8-LAB8.i386.rpm
Wrote: /usr/src/redhat/RPMS/i386/php4-snmp-4.4.8-LAB8.i386.rpm
Wrote: /usr/src/redhat/RPMS/i386/php4-domxml-4.4.8-LAB8.i386.rpm
Wrote: /usr/src/redhat/RPMS/i386/php4-xmlrpc-4.4.8-LAB8.i386.rpm
Wrote: /usr/src/redhat/RPMS/i386/php4-mbstring-4.4.8-LAB8.i386.rpm
Wrote: /usr/src/redhat/RPMS/i386/php4-ncurses-4.4.8-LAB8.i386.rpm
Wrote: /usr/src/redhat/RPMS/i386/php4-gd-4.4.8-LAB8.i386.rpm
Executing(%clean): /bin/sh -e /var/tmp/rpm-tmp.55937
+ umask 022
+ cd /usr/src/redhat/BUILD
+ cd php-4.4.8
+ '[' /var/tmp/php4-root '!=' / ']'
+ rm -rf /var/tmp/php4-root
+ rm files.domxml files.gd files.imap files.ldap files.mbstring files.mysql files.ncurses files.odbc files.pgsql files.snmp files.xmlrpc
+ exit 0

OpenLDAP info.

2011-03-20T15:52:00.000-07:00

I found a great post in a mailman mail list: http://www.openldap.org/lists/openldap-technical/201103/msg00026.html

I think ill be giving this a shot relatively soon :) Im kind of excited.

RE: OpenLDAP, Kerberos, Samba, PAM, How Do They Work Together?

* To: "Nan Meng" ,
* Subject: RE: OpenLDAP, Kerberos, Samba, PAM, How Do They Work Together?
* From: "Germ van Ek"
* Date: Wed, 2 Mar 2011 11:01:34 +0100
* Content-class: urn:content-classes:message
* In-reply-to: <4D6D73FB.6060805@gmail.com>
* References: <4D6D73FB.6060805@gmail.com>
* Thread-index: AcvYYzxAWgY6nws6RqWuejoq/SRO6AAWvsdw
* Thread-topic: OpenLDAP, Kerberos, Samba, PAM, How Do They Work Together?

Dear Nan,

I'll give it a go, my explanation will be simplified, as all software of
course is able to do a lot, I'll try to explain it's typical role.

OpenLDAP is a database management system. It communicates with database
clients in a standard (LDAP) way, and uses a (configurable) database
backend to store it's data.
One of the more popular database backends is Berkeley DB (BDB). It
usually stores it's data in files in /var/lib/ldap.

Kerberos is an authentication mechanism. It is ticket based. That means
that as soon as a client authenticates with Kerberos, it receives an
'authentication ticket'. It is then able to send this ticket to one or
more (thereby using single signon) services, such as Samba.

Samba is used for file sharing, printer sharing and Windows
authentication. It currently emulates a Windows NT4 domain controller.
It can use a LDAP server for it's user/groups backend.

PAM is the Linux 'Pluggable Authentication Mechanism'. This is
authentication system of Linux, that can use plugins for retrieving user
and group info. The 'standard' plugin is pam_unix, this uses the
familiar /etc/passwd,/etc/group and /etc/shadow files. Another plugin is
pam_ldap, which uses the LDAP configuration in /etc/ldap.conf for
authentication.

Another thing that probably will be configured is nsswitch. This is the
'name service switch', that resolves user id's (0 for root,1000 and up
for other users) to user names. This is configured in
/etc/nsswitch.conf. (passwd,shadow,group will most likely be configured
as 'files ldap').

The standard base for LDAP client configuration is /etc/ldap.conf.

The most likely thing to be down, if I read your story, is the LDAP DB,
and more deeper, your Berkeley DB.
Troubleshooting this has been a long time ago for me. The only thing
that comes into mind is trying to start slapd by hand (without the
init.d script) using a '-vvv' parameter for maximum verbosity. It will
then hopefully crash and tell you what is wrong in the end.

Regards,
Gerben

-----Oorspronkelijk bericht-----
Van: openldap-technical-bounces@OpenLDAP.org
[mailto:openldap-technical-bounces@OpenLDAP.org] Namens Nan Meng
Verzonden: dinsdag 1 maart 2011 23:32
Aan: openldap-technical@openldap.org
Onderwerp: OpenLDAP, Kerberos, Samba, PAM, How Do They Work Together?

Dear list members,

I hope amateur questions could be tolerated. I would make it
professional if I could. I'm a newbie to OpenLDAP and probably even
Linux, but I have to take care of an office network (Linux servers with
Linux and PC workstations) that features email server, domain control,
file/printer sharing, user account management, web servers and so forth,
on my own without anyone's help.

Yesterday morning the power went down and so did our servers. After I
turned the servers back on, the account information system was no longer
working. Users weren't able to login with their credentials anymore,
even the root. What I did was I logged in the server (the Samba PDC,
LDAP server, Kerberos server, domain controller, email server) with
single mode, reseted the root password, and added accounts for other
individual users on the server. I know it was a bad idea. Although I got
some things working (emails, file/printer sharing), but there are still
other problems (PHP ldap_bind() from web servers fails, domain user
accounts and profiles fail to load correctly).

I know there is a centralized mechanism that handles user accounts with
the help of OpenLDAP, Kerberos, Samba, BerkeleyDB (and possibly other
things), but I don't have a clue of how they work together. I've been
trying to learn from docs and books for a long time before this power
issue, but not very successful.

My greatest problem is that I don't know how these things are working
together on my system. I believe I also lack some fundamental system
knowledge. I've been reading the docs available, but they're so abstract
to me and none of them seems to match our system configuration.

I'm hoping that I can get some help from here. Maybe some one can give
me some suggestions on how to troubleshoot in such a scenario as a
newbie, or an entry point that I can follow in order to explore the
system. I believe you can tell that I'm totally confused here without
being able to give much useful information about the problem and the
system. I'm sorry for my ignorance, but I really tried to deal with it
myself. If this thread turns out to be annoying or ridiculous, please
ignore, and I do apologize.

However, while I'm still struggling on the problem, if anyone could
help, I would really appreciate it. Thank you so much.

N.M.

--

A Open Source Wish

2010-12-19T01:30:00.000-08:00

My wish is for some day open source software to to end the era of paying for software. No patents, No Licenses, and no more frivolous law suits. My dream is to some day walk into a school and see a school not limited to the software that it can provide its students due to price tags and silly licenses. A educational establishment that has endorsed its roots of learning and not paying for sub par pre-cooked software packages.

I know I haven't written much since I started at the new places but with the year comes a whole new set of blogs with information for the masses.

What Linux means to me...

2010-10-26T02:31:00.000-07:00

Intellectual freedom to do what ever I want with an OS as I see fit. If I want to put XFS across /var/lib/mysql , I can. It releases that angry beast that wants to make a smaller, simpler way to move mysql users from one DB to another. Its an OS that screams put me on everything with a microprocessor and well I have... Mipsel, Arch, Blackfin, Mini_X86, and many more. Linux can be eye candy or just a tty, but at the end of the day its the same.

I often refer to Linux in comparison to, "Give me Liberty or Give me Death". Why you ask? Think of it this way, " Give me an operating system where I can do what I want, or give me no operating system at all". I have left windows far behind because of its limitations and its lack of sensibly features and expandability.

I will admit I was once a Windows person but no more. In the last 7 years my eyes have have been opened to the point where I see clearly that windows was an error of an era past. I no longer look at it like its a gem but more of another stone of yesteryear along with things like DEC VAX, VOS, HP UX, AIX, and MAC. I feel I have transcended relic file systems such as NTFS, and HFS.

I have chosen a field and a line of work that was some what called experimental while I was growing up to find that I am one of the few, the brave, and the daring enough to challenge the norm of what was modern contemporary computing. I did not concede to getting a MCSA or MCSE, but have decided to fore go those relics of IT. Linux has kept me employed during a recession and where people have been fighting over jobs I had multiple interviews with little to no equal competition. I have always looked up to Linux innovators such as Richard Stallman, and Linus Torvald. I know that I may never contribute as highly as they have to the cause and Im alright with that but I contribute where it is needed in support.

I have dedicated many waking hours to becoming the phenom that I am, and I wont ever stop because I want to see a change in modern computing. The change I speak of is a world where closed operating systems have a smaller market share then open operating systems. I applaud innovators like RedHat/Centos, and Ubuntu that are starting to hack away at the difference. Those playgrounds for new people, new desktop alternatives, and new server-centric operating systems are being born. Not just born, nurtured by new ideas and new innovations.

I say,"Give me your tired, your poor/Your huddled masses yearning to breathe free". I say, " Breathe easier the monopolies will some day disappear and the oppression will end, and we will suffer no longer."

On that note I'm off to bed - Night all

Unix: Minix3 ( A minimal Unix Clone )

2010-08-25T11:21:00.000-07:00

Minix3
Website: http://www.minix3.org/
Download: http://www.minix3.org/download/

An introduction from the Minix 3 site:

"What Is MINIX 3?
MINIX 3 is a new open-source operating system designed to be highly reliable, flexible, and secure. It is loosely based somewhat on previous versions of MINIX, but is fundamentally different in many key ways. MINIX 1 and 2 were intended as teaching tools; MINIX 3 adds the new goal of being usable as a serious system on resource-limited and embedded computers and for applications requiring high reliability

This new OS is extremely small, with the part that runs in kernel mode under 6000 lines of executable code. The parts that run in user mode are divided into small modules, well insulated from one another. For example, each device driver runs as a separate user-mode process so a bug in a driver (by far the biggest source of bugs in any operating system), cannot bring down the entire OS. In fact, most of the time when a driver crashes it is automatically replaced without requiring any user intervention, without requiring rebooting, and without affecting running programs. These features, the tiny amount of kernel code, and other aspects greatly enhance system reliability."
~http://www.minix3.org/

Some of the greatest news to come to Minix 3 recently is that it was entered in Google's Summer of Code which will add mature code to jump start this minimal OS.

Url: http://wiki.minix3.org/en/SummerOfCode2010

Projects:
MINIX firewall
Multiboot compliance
Porting Pkgsrc
Unix domain sockets

I will have a couple follow-up segments in regards to Minix 3, but I encourage people to give it a shot. I understand its not for everyone though :)

Alien - A conversion tool for packages :)

2010-08-25T10:59:00.000-07:00

I rarely find a case where Fedora/Centos/Rhel lacks a package for something on debian/ubuntu. In fact as mature package management systems become increasingly common such as emerge,yum, dpkg/apt, yast, and pkgsrc. I expect this will become increasingly rare amongst distro's as time goes on. In the long run there are few solutions but there is one I prefer... Alien :)

Alien
Website: http://kitenet.net/~joey/code/alien/
Source URL: http://packages.debian.org/unstable/source/alien
GIT: git://git.kitenet.net/alien
Apt: sudo apt-get install alien

Conversion of an *.deb file to *.rpm file.

Usage:

workbox:~/Downloads$ wget https://sourceforge.net/projects/debreate/files/debreate/0.7/debreate_0.7.0-0_all.deb/download

workbox:~/Downloads$ sudo alien -r --scripts debreate_0.7.0-0alpha5_all.deb
debreate-0.7.0-1.noarch.rpm generated

Most notably this conversion tool works with the following formats:

Rhel/Centos/Fedora : rpm
Debian/Ubuntu : deb
Stampede : slp
Slackware/Slax : tgz
Solaris/*BSD : pkg

Enjoy!

Linux: TRK ( Trinity Rescue Kit )

2010-08-06T10:08:00.000-07:00

This week my company fired our SEO guy, Eh.. That wasnt pretty and such. Most notably when you have those situations where it was not under great terms you find "repurposing" there work station becomes a nightmare.

The set up was a machine with Windows 7, and the only user was the guy who was
fired and his password. His password of course wasn't documented anywhere so I was left to the task of getting in.

In another life I was into stuff like bypassing and all that jazz. I went out on the internet and with in a few searches I found the right "tool" for the "job".

Trinity Rescue Kit

Homepage Url: http://trinityhome.org/Home/index.php?wpid=1&front_id=12
Download Url: http://trinityhome.org/Home/index.php?wpid=165&front_id=12

I did the following:
1. Downloaded the trk iso & put my thumbdrive(2gb) in the machine.
2. Mounted the iso to a VM on virtualbox (Non-OSE)
3. Enabled usb passthrough in virtualbox for my thumbdrive.
4. Booted the iso, and hit the default boot option
5. At command promt:
$> mountallfs
$> trk2nfs -d /dev/sda -s 1024
~~~~ Waited for it to do its thing ~~~~
$> reboot
6. turned off the virtual machine and removed my thumbdrive.
7. moved over the the former employee's work station.
8. booted machine, and edited the bio's to boot from the thumbdrive.
9. let trk start up and then selected default boot.
10. At command promt:
$> mountallfs
$> winpass
4) to unlock the administrators account (might have this to do a few times it didnt stick the first time.
$> winpass
3) to wipe the password for that account.
$> reboot
11. wait for it shutdown.
12. pull thumbdrive and let system boot normally.
13. Login as administrator, reset account passwords and such.

^^ Have fun

How memory Profiles differ from VPS/Guest Host/Actual System

2010-07-30T10:31:00.000-07:00

Device profiles are able to actually help us determine the locations of memory but also can help you profile a system. In this post Im providing some outputs of VPS/Guest Host/Actual Systems so you can see the difference.


OpenVZ:

root@bucket:~# lshw -short -class memory
H/W path  Device  Class      Description
========================================
/0/0              memory     1GiB System memory

Above is our OpenVZ Linux Box. Not much to see here its a singular 
memory channel 1GB of ram.

----------------------------------------------------------------

VirtualBox Guest Host:

dnsbox@dnsbox:~$ sudo lshw -short -class memory
[sudo] password for dnsbox: 
H/W path          Device      Class       Description
=====================================================
/0/0                          memory      128KiB BIOS
/0/1                          memory      511MiB System memory
/0/2/0                        memory      128KiB L1 cache
/0/2/1                        memory      1MiB L2 cache

Similar to the OpenVZ as in 0/1 being a singular memory channel 
however abit more robust in providing Cache and L1/L2.

CPUs Cache:
/0/2/0                        memory      128KiB L1 cache
/0/2/1                        memory      1MiB L2 cache

----------------------------------------------------------------

Real Host:

melinko2003@workbox:~$ sudo lshw -short -class memory
H/W path      Device      Class          Description
====================================================
/0/0                      memory         128KiB BIOS
/0/3/a                    memory         128KiB L1 cache
/0/3/b                    memory         1MiB L2 cache
/0/11                     memory         3GiB System Memory
/0/11/0                   memory         512MiB DIMM DDR2 667 MHz (1.5 ns)
/0/11/1                   memory         1GiB DIMM DDR2 667 MHz (1.5 ns)
/0/11/2                   memory         1GiB DIMM DDR2 667 MHz (1.5 ns)
/0/11/3                   memory         512MiB DIMM DDR2 667 MHz (1.5 ns)
/0/4/0                    memory         128KiB L1 cache
/0/4/1                    memory         1MiB L2 cache
/0/a                      memory         RAM memory
/0/1.2                    memory         RAM memory

Above is my workstation which actually provides some indication 
that it is a physical machine. How? Take a look:

/0/11                     memory         3GiB System Memory
/0/11/0                   memory         512MiB DIMM DDR2 667 MHz (1.5 ns)
/0/11/1                   memory         1GiB DIMM DDR2 667 MHz (1.5 ns)
/0/11/2                   memory         1GiB DIMM DDR2 667 MHz (1.5 ns)
/0/11/3                   memory         512MiB DIMM DDR2 667 MHz (1.5 ns)

Device /0/11 is the systems PC5300 memory bank. 
Device /0/11/0 is the first memory module in the bank and so on.

We can actually derive abit more information from above.This System 
highly like has 2 CPU's or is a dual-core system:

First CPU's L1/L2 Cache:
/0/3/a                    memory         128KiB L1 cache
/0/3/b                    memory         1MiB L2 cache

Second CPU's L1/L2 Cache:
/0/4/0                    memory         128KiB L1 cache
/0/4/1                    memory         1MiB L2 cache

Of course we have BIOS:
/0/0                      memory         128KiB BIOS

Some Misc Memory controls for the chipset: 
/0/a                      memory         RAM memory
/0/1.2                    memory         RAM memory

Free 50GB of storage online

2010-07-29T11:47:00.000-07:00

I was surfing around and found : https://www.adrive.com/login/signup

The Basic plan gives you 50GB of free storage. Thats CRAZY!

Pidgin: Facebook Plugin

2010-07-28T13:34:00.000-07:00

Today I just happened to have stumbled upon this plugin for Pidgin. Its a plugin that allows you to chat with facebook friends :D Woot!

http://code.google.com/p/pidgin-facebookchat/

Linux: How to tell if you are Link UP

2010-07-28T11:12:00.000-07:00

I was reviewing some of the most common interview questions asked to Linux Systems Administrators. I saw a great one:

Q. "How can you tell if an interface is link up?"

A. I guessed the old fashion one:
$>ifconfig eth0


Alternative answers:
$>ethtool eth0
Settings for eth0:
     Supported ports: [ MII ]
     Supported link modes: 10baseT/Half 10baseT/Full
     100baseT/Half 100baseT/Full
     Supports auto-negotiation: Yes
     Advertised link modes: 10baseT/Half 10baseT/Full
     100baseT/Half 100baseT/Full
     Advertised auto-negotiation: Yes
     Speed: 100Mb/s
     Duplex: Full
     Port: MII
     PHYAD: 1
     Transceiver: external
     Auto-negotiation: on
     Supports Wake-on: g
     Wake-on: d
     Link detected: yes

*Interesting enough ethtool provides us some more key info see color code below for more details:
     Current Duplex rate of device: [#]
     Current Speed of device: [#]


$>ip link show
1: lo: loopback,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
link>loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: broadcast,multicast,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link>ether 00:1e:8c:6e:e0:4f brd ff:ff:ff:ff:ff:ff
4: vboxnet0: broadcast,multicast\>mtu 1500 qdisc noop state DOWN qlen 1000
link>ether 0a:00:27:00:00:00 brd ff:ff:ff:ff:ff:ff

$> dmesg  grep eth
[ 0.238932] ACPI Error (psparse-0537): Method parse/execution failed [\_SB_.MEM_._CRS] (Node f7019b70), AE_AML_BUFFER_LIMIT
[ 0.238957] ACPI Error (uteval-0256): Method execution failed [\_SB_.MEM_._CRS] (Node f7019b70), AE_AML_BUFFER_LIMIT
[ 2.230873] forcedeth: Reverse Engineered nForce ethernet driver. Version 0.64.
[ 2.231181] forcedeth 0000:00:07.0: PCI INT A -> Link[APCH] -> GSI 23 (level, low) -> IRQ 23
[ 2.231185] forcedeth 0000:00:07.0: setting latency timer to 64
[ 2.748879] forcedeth 0000:00:07.0: ifname eth0, PHY OUI 0x732 @ 1, addr 00:1e:8c:6e:e0:4f
[ 2.748883] forcedeth 0000:00:07.0: highdma pwrctl mgmt lnktim msi desc-v3
[ 13.217598] forcedeth 0000:00:07.0: irq 26 for MSI/MSI-X
[ 805.825023] device eth0 entered promiscuous mode

**** Note this last case will tell you if link fluxes happen.

Migrating from virtualbox-3.0 to virtualbox-3.2

2010-07-26T09:57:00.000-07:00

I tend to have the attitude of... "If its not broken, dont fix it.
Well today after some testing over the last few weeks on a few other
systems I migrated virtualbox-3.0 to virtualbox-3.2 on my PC.

Just a small primer on how i did it:

$> sudo wget http://download.virtualbox.org/virtualbox/3.2.6/virtualbox-3.2_3.2.6-63112~Ubuntu~karmic_i386.deb
$> sudo apt-get remove virtualbox-3.0
$> sudo dpkg --install virtualbox-3.2_3.2.6-63112~Ubuntu~karmic_i386.deb
$> sudo echo "deb http://download.virtualbox.org/virtualbox/debian karmic non-free" >> /etc/apt/sources.list
$> sudo wget http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc
$> sudo apt-key add oracle_vbox.asc
$> sudo apt-get update

Enjoy!

wget: Rate limiting Downloads

2010-07-26T09:53:00.000-07:00

Nifty little feature i've ran across recently in wget:

wget http://mysqltuner.pl/ --limit-rate=5K

Essentially what this will do is.

1) "Wget http://mysqltuner.pl/" get the contents of mysqltuner.pl website
2) "--limit-rate=5K" limit the download rate to 5K ( equivalent of 56K modem. )

Building a PC for under 200$

2010-07-26T09:38:00.000-07:00

When I was in High School, mind you - I graduated in 2003, a computer for 200$ was far far away. You could get a name-brand CD burner for 200$ but that was about it. I think 500$ at that time was pretty reasonable for a P III 500mhz up to maybe P4 2GHZ the whole span of those 4 years.

Gaming Rigs at those times were 1K-4K depending on how cutting edge you wanted to go. The lower end gaming rigs at that time were around 800-900$ mids were in the 900$-1000$ range.

Over the last 7 almost 8 years since I've graduated I've built rigs for people on and off that have been consistently going down in price. I've actually priced out some low-end gaming rigs for around 300$, not including Monitor/keyboard/mouse.

I find mid-level gaming rigs to reach from about 400-700$ and High End still 800$+.
Systems that do not need this kind of speed and such are easily in the 200$ range.

I found this link today and thought I would share it with you :)

http://www.extremetech.com/

Debian: Bandwidth limiting apt

2010-07-06T16:10:00.000-07:00

I enjoy tools like yum and apt, but wheres the control for limited bandwidth or shared bandwidth environments. Its not a magic options... or is it?

Example:
$> sudo apt-get -o Acquire::http::Dl-Limit=25 upgrade

Limits downloads to 25k. However how do i do this with a distro upgrade via cli?

sudo aptitude update &&
sudo aptitude -o Acquire::http::Dl-Limit=25 safe-upgrade &&
sudo aptitude -o Acquire::http::Dl-Limit=25 full-upgrade

Should set you at a pretty steady 25K upgrade process.. might take a couple hours but its worth it.

PHP: Email Sanitization code.

2010-06-18T09:48:00.000-07:00

So the principal thought behind this is to have a function that determines weather an email address is crap or not crap based on the functions return. Return 1, your email is bad juju, return anything else your fine.

So an example of usage:

Your going to import email leads from a database and you need to check weather the email address is valid.

Query DB -> Grab $Info + $email -> sanitize($email)
-> return(1) -> Notify of Deletion -> Query(Delete($emails))
-> return(x) -> Notify of Completion -> Query(insert($info + $email))



Php Code starts here:

/* Character Omission:
!@#$%^&*()`'/\{}~ ,<>":;[] (and unicode characters like §, ™, ®, ⚛, ⚡, ö, π, and the like)

(1) ."a" is appended due to a bug in php. Found:
http://www.php.net/manual/en/function.mb-detect-encoding.php#81936 
*/

function sanitizer($email){
    $email = explode('@',$email);
    $intergity = count($email);
    if($intergity <= 2){
 $email = $email[0].$email[1];
 $email = preg_split('//', $email, -1);
 foreach($email as $char){
      if( mb_detect_encoding($char.'a', "auto") == "ASCII")
      {switch($char){ 
  case '!': { return 1; break; }
  case '?': { return 1; break; }
  case '@': { return 1; break; }
  case '#': { return 1; break; }
  case '$': { return 1; break; }
  case '&': { return 1; break; }
  case '^': { return 1; break; }
  case '>': { return 1; break; }
  case '<': { return 1; break; }
  case '&': { return 1; break; }
  case '*': { return 1; break; }
  case '(': { return 1; break; }
  case ')': { return 1; break; }
  case '`': { return 1; break; }
  case "'": { return 1; break; }
  case '/': { return 1; break; }
  case '\\': { return 1; break; }
  case ' ': { return 1; break; }
  case '{': { return 1; break; }
  case '}': { return 1; break; }
  case '~': { return 1; break; }
  case ',': { return 1; break; }
  case '"': { return 1; break; }
  case ':': { return 1; break; }
  case ';': { return 1; break; }
  case "[": { return 1; break; }
  case ']': { return 1; break; }
  default: {break;}}
     }else{return 1;}
        }
    }else{return 1;}
}

if(!sanitizer('test@test.com') == 1)
{ echo "it works"; }else{ echo "nope, crap";}
?>"

So Its Basically a few "if" statements to check logic of an email, another "if" statement combined with a encoding function then to round it out with a case statement. Obviously this is left really open for you to add your own status codes and such with the returns.

Apache ServerSignature tutorial

2010-06-09T14:19:00.000-07:00


Sometimes webserver security comes down to not providing information to an attacker. In terms of Apache2 masking the signature can be a very critical piece. Below I will explain how to mask the signature and how to verify its masked with nmap.

Stock Apache2 install:
$>sudo nmap -PO -A -O -vvv 192.168.2.75
... Text ...
80/tcp   open  http        Apache httpd 2.2.11 ((Ubuntu) DAV/2 SVN/1.5.4 PHP/5.2.6-3ubuntu4.5 with Suhosin-Patch mod_ssl/2.2.11 OpenSSL/0.9.8g)
.... More Text ....
443/tcp  open  ssl/http    Apache httpd 2.2.11 ((Ubuntu) DAV/2 SVN/1.5.4 PHP/5.2.6-3ubuntu4.5 with Suhosin-Patch mod_ssl/2.2.11 OpenSSL/0.9.8g)                                         
.... More Text ....

We don't want to give that information to 3rd parties or even worse hackers. So we will do the following below:

$>sudo nano /etc/apache2/apache2.conf
ServerSignature Off
ServerTokens Prod
$>sudo /etc/init.d/apache2 reload

Muted Apache2 server now:

$>sudo nmap -PO -A -O -vvv 192.168.2.75
...NMAP Text ...
80/tcp   open  http        Apache httpd 
.... More Text ....
443/tcp  open  ssl/http    Apache httpd                                          
.... More Text ....

For alternative modifications I would suggest looking at:
http://httpd.apache.org/docs/2.2/mod/core.html#servertokens
http://httpd.apache.org/docs/2.2/mod/core.html#serversignature

:) Hope this provided some insite

Backing up a live MySQL DB w/o Locking its tables!

2010-04-12T09:13:00.000-07:00

I recently had a project that we have to build a back up tool for our databases. Along time ago I was told by a supervisor that it was essentially impossible to back up a live sql DB with out locking its tables. After literally 5 to 10 minutes of googling and looking through documentation I came up with this, and it works!

mysqldump -u username -ppassword -h hostname --opt --skip-lock-tables --single-transaction db_name > db_name.sql

Hope this helps!

Cross Compiling

2010-03-23T14:32:00.000-07:00

Cross Compiling: Compiling for a Different Chip Architecture.

For anyone who has ever considered compiling applications for arm/mipsel/mips/etc but never knew where to start. Take a look this site contains some decent tutorials and also some prebuilt tools per OS.

http://kegel.com/crosstool/crosstool-0.43/doc/crosstool-howto.html#all

TECH DEAL: 99$ HP Dual Xeon 3.06GHz 1U Server

2010-03-23T09:31:00.000-07:00

HP SERVER DL140 DEAL:

http://www.pacificgeek.com/product.asp?ID=856143