tag:blogger.com,1999:blog-67636852025-08-31T02:40:15.467-04:00Virtual WorldUnknownnoreply@blogger.comBlogger17125tag:blogger.com,1999:blog-6763685.post-26571433747240206772019-10-20T21:48:00.002-04:002019-10-20T21:58:36.094-04:00Terminal or Vi hangs after pressing ctrl + sPeople who used to editors with shortcut CTRL + s to save files may have developed a habit to hit CTRL + s reflexively.
I do the same. So, when I was using Vi, I may also accidentally pressed CTRL + s, which paused my terminal. Don't worry. Everything is fine. Simply press CTRL + q and the terminal will resume.
Picture: Pumpkins in Minnesota Arboretum. Oct. 2017
Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-2669596352532244052019-10-12T01:07:00.000-04:002019-10-12T01:07:09.720-04:00x11 forwarding for Microsoft Windows and GitBash 1. Install Xming. Then, start the Xming X server.
2. Open GitBash.
3. Export display environment on the bash command.
export DISPLAY=localhost:0
4. ssh to the target machine with x11 forwarding enabled
ssh -XY username@remote.host
5. Try your x11 forwarding by running an application with GUI, such as gedit.
Enjoy your X window.
Picture: Sunset Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-11434658298794107622013-10-04T23:58:00.000-04:002013-10-13T01:21:15.834-04:00LATEX ERROR: paragraph ended before \@citex was complete
While I was compiling my paper with ACM sigplan template, I get a lot of error messages like this:
paragraph ended before \@citex was complete
I could only know there is something wrong in citations/references. But, I had no clue of how to fix it.
I firstly read the Author’s Guide to the ACM SIGPLAN Class (sigplanconf.cls). It states that SIGPLAN class wants the bibliography to be included in Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-71588862718164279262013-10-03T18:04:00.001-04:002013-10-13T01:21:25.135-04:00CloudSuite - Cassandra server - out of memory errorWhile I was trying to run YCSB with Cassandra on VM, which has 1 VCPU and 512 MB memory.
When I was using run_load.command (from CloudSuite package) to populate the store, the Cassandra server keeps crashing and reporting
java.lang.OutOfMemoryError: Java heap space
After trying different parameter combinations, I finally successfully populated the data store.
Let me describe how I Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-86291088991098599312013-10-02T17:56:00.000-04:002013-10-13T01:21:38.313-04:00CloudSuite - Cloud9 compiling issues
Environment: Linux 3.5 Ubuntu 12.10
LLVM 2.9 building error
Building Cloud9 in CloudSuite from EPFL requires LLVM.
While compiling LLVM, I had this error
Intercept.cpp:69:67: error: lseek64 was not declared in this scope
This can be solved by adding #include < unistd.h > into Intercept.cpp.
Referece:
http://bugs.debian.org/cgi-bin/Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-47315020496993253742013-09-25T16:55:00.000-04:002013-10-13T01:21:54.870-04:00Error while loading shared libraries "libiomp5.so"
OS: Ubuntu 13.04 (Linux kernel 3.8)
Compiler: Intel Composer XE 2013 SP1
I finally build the ARP benchmark from NU-MineBench.
When I try to run it, however, it shows
Error while loading shared libraries "libiomp5.so"
This is because an environment variable called LD_LIBRARY_PATH is not correctly configured.
This can be solved by typing
source /opt/intel/bin/compilervars.sh Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-61017768546356327512013-08-23T10:01:00.002-04:002013-10-13T01:22:14.391-04:00Compiling problem: XXX.c:##:##: fatal error: XXX/XXX/XXX.h: No such file or directory
When you download a source package and try to build the program from the source code, chances are that the README file can not list all prerequisite for you. As a result, for example, you will see something like this:
glut_input.c:22:35: fatal error: X11/extensions/XInput.h: No such file or directory
On a Ubuntu/Debian system, you can use apt-file to solve this problem. For example, you can Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-1370944907699668642013-08-19T21:33:00.003-04:002013-10-13T01:22:34.065-04:00KVM: How to find a guest VM's process ID (PID)There are two ways to find VCPUs' PID.
Suppose the testing VM is named GUEST_X and it has 4 VCPUs.
Method A:
If you are using libvirt to manage VMs.
You can type:
sudo grep pid /var/run/libvirt/qemu/GUEST_X.xml
Then, you will see VCPUs' PID like this:
<domstatus state='running' reason='booted' pid='6556' ><vcpu pid='6558'/ ><vcpu pid='6559'/ ><Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-59770101197312099332013-03-24T13:13:00.002-04:002013-08-19T22:03:32.568-04:00Error: Boot loader didn’t return any dataI have a Ubuntu 12.04 guest VM. Host machine is running Ubuntu 12.04 with Xen 4.1.
After installing a new kernel in guest VM and reboot. I got
Error: Boot loader didn’t return any data
After googling this, I found this pygrub seems have problems in parsing certain grub2 format.
I could not find any patches to fix this. Instead, I found some people workaround this problem by using grub, not Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-88958802466563579692013-03-11T13:21:00.002-04:002013-10-13T01:23:31.133-04:00Ubuntu12.04 libvirt virbr0 network bridge setupOffical Ubuntu website provides a very good and thorough guide for installing Xen in Ubuntu.
But, I personally prefer libvirt for managing network bridges, not changing network configuration as stated in the official website. So, I install libvirt:
sudo apt-get install libvirt0
Then type
virsh net-list --all
It shows nothing!!? That is because on Ubuntu. You need to add user to Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-57874510235208081682013-03-11T12:47:00.003-04:002013-10-13T01:23:47.675-04:00Use virt-install to create a Xen guest VM Host environment: Ubuntu12.04+Xen4
I personally prefer virt-manager. But, virt-manager is not always available. So, This post demonstrates how to install a ubuntu 12.04 LTS using virt-install without graphical user interface.
sudo virt-install --name testVM --ram 512 --vcpus=1 --disk ~/testVM.img,size=8 --location http://archive.ubuntu.net/ubuntu/dists/precise/main/installer-amd64/
If you wantUnknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-32102657802530777792013-03-09T14:43:00.001-05:002013-10-13T01:24:06.444-04:00How to customize and build Ubuntu server 12.04 LTS kernel1. Prepare building environment
sudo apt-get build-dep linux-image-$(uname -r)
2. Install required packages
sudo apt-get install libncurses5-dev kernel-package fakeroot build-essential crash kexec-tools makedumpfile kernel-wedge libelf-dev asciidoc binutils-dev
3. Create a source directory and get kernel source
mkdir ~/ubuntu-kernel-srccd ~/ubuntu-kernel-srcapt-get source Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-86367739815662327782013-03-02T14:03:00.000-05:002013-08-19T22:03:32.575-04:00How to create/remove a software RAID on Ubuntu
Creat a software RAID
First, get mdadm
apt-get install mdadm
Then, assume that we are using sdd and sdf to create a RAID0 called md0
mdadm --create --verbose /dev/md0 --level=stripe --raid-devices=2 /dev/sdd /dev/sdf
Here is a good article for more detail options.
Then, you can partition, format, and mount /dev/md0 as you do to other disks.
Remove a software RAID
Step 1. Unmount the RAID.
Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-57609830189729434452013-02-23T23:14:00.001-05:002013-08-19T22:03:32.565-04:00virt-manager / virt-install: unable to connect to 'localhost:8000': Connection refusedThis should be a bug on Ubuntu 12.10 + Xen 4 + virt-manager. This problem also exists on Ubuntu12.04 LTS + Xen 4 + virt-install
Solution/Workaround:
In "/etc/xen/xend-config.sxp",
uncomment the following lines:
(xend-unix-server no)
(xend-unix-path /var/lib/xend/xend-socket)
Then, change
(xend-unix-server no)
to
(xend-unix-server yes)
Reboot.
Reference:
https://bugs.launchpad.net/ubuntu/+Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-1225097615932761702013-02-23T20:35:00.002-05:002013-10-13T01:24:48.015-04:00get xen-syms from building source on ubuntuStep 1.
apt-get source xen-hypervisor-4.1-amd64
Step 2.
cd xen-4.1.3
Step 3.
make world
If you did not install any required packages. You may have a painful experience as I had.
Before looking into problems, here is the summary of required packages from experiencing problems below:
apt-get install libx11-dev uuid-dev bin86 bcc gcc-multilib ipxe iasl libaio-devUnknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-82518115313482912032013-02-22T23:54:00.000-05:002013-08-19T22:03:32.573-04:00My experience on installing xenoprofBoth xenoprof and oprofile website provides clear installation guideline.
So, this post shares the problems I had in the installation and the solutions.
Oprofile version: 0.9.5 (remember to patch xenoprof before you go on)
Ubuntu 12.10 with Xen 4
First,
"./configure --with-kernel-support" because kernels > 2.6 include oprofile
During configuration, I got two problems.
1. Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6763685.post-6812937148029097022013-02-21T23:33:00.002-05:002013-08-19T22:03:32.570-04:00How to move a VM between hosts? (Not migrate)Many posts talk about migration.
But, how do we move a VM from one host to another?
This sounds like an easy task but it is not easy to find an how-to on Internet.
So, let's start an easy how-to.
We use Xen 4.0 in this example.
Assume the VM name is Tutorial and it has a virtual disk image file called Tutorial.img
1. Copy/Move virtual disk files.
If both machines are connected on network and Unknownnoreply@blogger.com0