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Dobrica Pavlinušić's random unstructured stuff
OpenVZ: Revision 11
"OpenVZ"<http://www.openvz.org/> is nice name-space virtualization, creating chroot jails on steroids, similar in spirit to Solaris zones. It ideal if you want to run single kernel and allocate resources using bean counters as opposed to hard-limits (20% of CPU as opposed to one core). Each slice is called `VE`.
{toc: } ^ Disk speed .pre dpavlin@zut:~$ sudo hdparm -tT /dev/cciss/c1d0 /dev/sda /dev/cciss/c1d0: Timing cached reads: 2184 MB in 2.00 seconds = 1092.39 MB/sec Timing buffered disk reads: 324 MB in 3.02 seconds = 107.40 MB/sec /dev/sda: Timing cached reads: 2144 MB in 2.00 seconds = 1071.89 MB/sec Timing buffered disk reads: 136 MB in 3.02 seconds = 45.02 MB/sec .pre Insert joke about "enterprise storage"<http://images.google.com/images?hl=en&q=enterprise+storage> ^ Add disk space to VE We are using normal Linux LVM with single logical volume for all VEs. First, resize logical volume: .pre root@koha-hw:~# vgextend -L +80G /dev/vg/vz vgextend: invalid option -- L Error during parsing of command line. root@koha-hw:~# lvextend -L +80G /dev/vg/vz Extending logical volume vz to 100.00 GB Logical volume vz successfully resized root@koha-hw:~# resize2fs /dev/vg/vz resize2fs 1.40-WIP (14-Nov-2006) Filesystem at /dev/vg/vz is mounted on /vz; on-line resizing required old desc_blocks = 2, new_desc_blocks = 7 Performing an on-line resize of /dev/vg/vz to 26214400 (4k) blocks. The filesystem on /dev/vg/vz is now 26214400 blocks long. root@koha-hw:~# df -h /vz/ Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg-vz 99G 20G 79G 21% /vz .pre Then, take a look how much space does VEs take: .pre root@koha-hw:~# vzlist -o veid,diskspace,diskspace.s,diskspace.h,diskinodes,diskinodes.s,diskspace.h VEID DQBLOCKS DQBLOCKS.S DQBLOCKS.H DQINODES DQINODES.S DQBLOCKS.H 212052 11717220 15728640 20971520 61001 286527 20971520 212226 6407804 10485760 12582912 69011 435472 12582912 .pre alternativly, you can also execute df inside VEs: .pre root@koha-hw:~# vzlist -o veid -H | xargs -i sh -c "echo --{}-- ; vzctl exec {} df -h" --212052-- Filesystem Size Used Avail Use% Mounted on simfs 15G 12G 3.9G 75% / tmpfs 2.0G 0 2.0G 0% /lib/init/rw tmpfs 2.0G 0 2.0G 0% /dev/shm --212226-- Filesystem Size Used Avail Use% Mounted on simfs 10G 6.2G 3.9G 62% / tmpfs 2.0G 0 2.0G 0% /lib/init/rw tmpfs 2.0G 0 2.0G 0% /dev/shm .pre next, we will set diskpace on both VEs (becase we want them to share all available resources) to new logical volume size: .pre root@koha-hw:~# vzlist -o veid -H | xargs -i vzctl set {} --diskspace 100G:100G --save Saved parameters for VE 212052 Saved parameters for VE 212226 .pre This VEs are not in production, and one is development version of another. When we move to production, we want to enforce more strict limit on disk usage, to protect production machine from running out of disk space in case the development one goes wild. ^ VE management We usually want to do some operations on bunch of VEs at once. This can be done using `vzctl exec` in one sweep like this: ^^ Update Debian .pre vzlist -H -o veid | xargs -i vzctl exec {} 'apt-get update && apt-get -y upgrade' 2>&1 | tee ~/log .pre ^^ Quick reporting You can read more about "groupby.pl and sum.pl on my blog"<http://blog.rot13.org/2008/05/group_by_data_in_shell_pipes.html>. .pre # install dependencies which are not part of standard lenny (sorry!) cpanp i IPC::System::Simple dpavlin@mjesec:~$ vzps -E axv --no-headers \ | groupby.pl 'sum:($7+$8+$9*1024),1,count:1' --join 'sudo vzlist -H -o veid,hostname' --on 2 \ | sort -rn | align | sum.pl -h webgui.rot13.org 23 1026M OOOOOOOOOOOO 1026M 0 385 855M OOOOOOOOOO------------ 1882M saturn.ffzg.hr 32 544M OOOOOO----------------------- 2427M eprints.ffzg.hr 18 351M OOOO----------------------------- 2778M arh.rot13.org 20 224M OO---------------------------------- 3003M .pre ^^ find getty processes .pre root@mljac:~# ps ax | grep getty | cut -c-5 | xargs vzpid Pid VEID Name 5668 0 getty 5670 0 getty 5672 0 getty 5673 0 getty 5674 0 getty 5675 0 getty 9503 207016 getty 9504 207013 getty 9505 207013 getty 9534 207016 getty 9535 207015 getty 9536 207013 getty 9537 207013 getty 9538 207015 getty 9539 207015 getty 9540 207015 getty 9541 207016 getty 9542 207015 getty 9543 207016 getty 9545 207013 getty 9546 207013 getty 9547 207015 getty 9548 207016 getty .pre ^ devices inside VE For example, "fuse"<http://wiki.openvz.org/FUSE> .pre dpavlin@brr:/dev$ vzctl set 100 --devices c:10:229:rw --save .pre ^ Links * "Recent Advances in the Linux Kernel resource management"<http://community.livejournal.com/openvz/27178.html> ^ vz-tools {include: [vz-tools]} ^ Related posts on my blog {fetchrss: http://blog.rot13.org/mt/mt-search.cgi?search=openvz&Template=feed&IncludeBlogs=1 full} |