Virtuozzo / Linux Reference

Updating VZ

Update Virtuozzo to version 4.0.0
Apply minor updates for Virtuozzo 3.0.0

... When you get to the last screen, you will be given an option to

( ) Automatically reboot after update
(*) Reboot later manually

make sure you choose to reboot later.

Migrating Templates

One nice feature VZ offers is the ability to run a virtual environment (VE or CT as it's now called) based on a particular ditribution on a host which may or may not share the same distribution. For instance, you could run a CT running Ubuntu while the host machine (Hardware Node or HN) is running CentOS. This is accomplished via the use of OS templates. As long as the HN contains the OS template on which a particular CT relies, it will run there. As such, if you want to move a CT from one HN to another, you will need to make sure the OS template exists there.

Modern versions of VZ (>= 4.x) will check for and automatically move the OS template over to the host as you're (vz)migrating the CT over to a new HN. However we like to make sure the template is in place prior to moving the CT.

The first step is to see if the template exists on the host. To see OS templates installed:

2.x (shows OS and application templates):

# vzpkgls
mod_ssl-rh9 20040624
mysql-rh9 20030814 20050412
openwebmail-rh9 20050427
php-rh9 20050506
phpBB-rh9 20041229
postgresql-rh9 20050719
sl-webalizer-rh9 20040119
spamassassin-rh9 20040127
tomcat-rh9 20040524
usermin-rh9 20040116

>= 3.x (shows just OS templates, run without -O to see application as well):

# vzpkg list -O
ubuntu-10.04-x86                   2010-06-01 11:39:05
ubuntu-11.04-x86                   2011-06-22 14:23:59
ubuntu-9.10-x86                    2010-03-11 17:39:51
centos-5-x86                       2010-03-11 17:12:27
debian-5.0-x86                     2010-03-11 17:33:34

All template files are located:

# ls /vz/template/
ColdFusion-fc1  jre-fc1               openwebmail-fc1     sl-webalizer-fc1
ColdFusion-fc2  jre-fc2               openwebmail-fc2     sl-webalizer-fc2
ColdFusion-rh9  jre-rh9               openwebmail-rh9     sl-webalizer-rh9
PostNuke-fc1    jre-suse92            openwebmail-suse92  spamassassin-fc1
PostNuke-fc2    jrun                  php-deb31           spamassassin-fc2
PostNuke-rh9    mailman-deb31         php-fc1             spamassassin-rh9
analog-fc1      mailman-fc1           php-fc2             spamassassin-suse92
analog-fc2      mailman-fc2           php-rh9             suse-9.2
analog-rh9      mailman-rh9           php-suse92          tomcat-fc1
awstats-fc1     mailman-suse92        phpBB-fc1           tomcat-fc2
awstats-rh9     mod_frontpage-fc1     phpBB-fc2           tomcat-rh9
bbClone-fc1     mod_frontpage-fc2     phpBB-rh9           tomcat-suse92
bbClone-fc2     mod_frontpage-rh9     phpmyadmin-deb31    urchin-fc1
bbClone-rh9     mod_frontpage-suse92  postgresql-deb31    usermin-fc1
conf            mod_perl-deb31        postgresql-fc1      usermin-fc2
debian-3.1      mod_perl-fc1          postgresql-fc2      usermin-rh9
devel-deb31     mod_perl-fc2          postgresql-rh9      uw-imap-fc1
devel-fc2       mod_perl-rh9          postgresql-suse92   uw-imap-fc2
devel-suse92    mod_perl-suse92       proftpd-deb31       uw-imap-rh9
fedora-core-1   mod_ssl-fc1           proftpd-fc1         vzredhat-7.3
fedora-core-2   mod_ssl-fc2           proftpd-fc2         vzredhat-8.0
jdk-deb31       mod_ssl-rh9           proftpd-rh9         webalizer-suse92
jdk-fc1         mysql-deb31           proftpd-suse92      webmin-fc1
jdk-fc2         mysql-fc1             redhat-7.2          webmin-fc2
jdk-rh9         mysql-fc2             redhat-9            webmin-rh9
jdk-suse92      mysql-rh9             redhat-as3-minimal
jre-deb31       mysql-suse92          redhat-devel-9

What we see here are the base OS templates: redhat-9, fedora-core-1 and supporting application templates: postgresql-rh9, mailman-rh9, jdk-fc1, mod_ssl-fc1. So if you wanted to copy over all of redhat 9 you'd need to copy the contents of:

# ls -d /vz/template/*rh9*
/vz/template/ColdFusion-rh9  /vz/template/mod_frontpage-rh9  /vz/template/proftpd-rh9
/vz/template/PostNuke-rh9    /vz/template/mod_perl-rh9       /vz/template/sl-webalizer-rh9
/vz/template/analog-rh9      /vz/template/mod_ssl-rh9        /vz/template/spamassassin-rh9
/vz/template/awstats-rh9     /vz/template/mysql-rh9          /vz/template/tomcat-rh9
/vz/template/bbClone-rh9     /vz/template/openwebmail-rh9    /vz/template/usermin-rh9
/vz/template/jdk-rh9         /vz/template/php-rh9            /vz/template/uw-imap-rh9
/vz/template/jre-rh9         /vz/template/phpBB-rh9          /vz/template/webmin-rh9
/vz/template/mailman-rh9     /vz/template/postgresql-rh9

# ls -d /vz/template/*redhat-9*
/vz/template/redhat-9

To get a template from one HN to another, it simply needs to be rsync'd over to the target HN. It's rsync'd over in this fashion:

rsync -av -e ssh /vz/template/redhat-9 root@10.1.4.65:/vz/template
rsync -av -e ssh /vz/template/*rh9 root@10.1.4.65:/vz/template

Newer (>= 3.x) VZ employs "EZ" templates which are organized a little differently:

# ls /vz/template/
cache   CmdTool.log  debian              redhat-as3-minimal-20080630.tar.gz  vc
centos  conf         redhat-as3-minimal  ubuntu

# ls /vz/template/ubuntu/
10.04  11.04  9.10
# ls /vz/template/ubuntu/10.04/
x86
# ls /vz/template/ubuntu/10.04/x86/
aap_1.091-1_all
aap-doc_1.091-1_all
adduser_3.112ubuntu1_all
anacron_2.3-13.1ubuntu11_i386
apache2_2.2.14-5ubuntu8.2_i386
apache2_2.2.14-5ubuntu8.4_i386
apache2_2.2.14-5ubuntu8.6_i386
apache2_2.2.14-5ubuntu8.7_i386
apache2_2.2.14-5ubuntu8.8_i386
apache2_2.2.14-5ubuntu8.9_i386
<...snip>

# ls /vz/template/cache/
centos-5-x86.tar.gz        suse-11.3-x86.tar.gz     ubuntu-9.10-x86.tar.gz
debian-5.0-x86.tar.gz      ubuntu-10.04-x86.tar.gz
fedora-core-14-x86.tar.gz  ubuntu-11.04-x86.tar.gz

So what we see is the entire OS and all applications are in 1 directory, and organized by distribution and release version. So to move Ubuntu 10.04:

rsync -av -e ssh /vz/template/ubuntu/10.04 root@10.1.4.69:/vz/template/ubuntu

and you also need to move the cache:

rsync -av -e ssh /vz/template/cache/ubuntu-10.04-x86.tar.gz root@10.1.4.69:/vz/template/cache/

Once the transfer is complete, you will be able to run vzpkgls or vzpkg list -O and see the template(s) listed on the target HN.

So far, this all supposes template doesn't exist on the target- very simple, just copy it over. If the template exists already on the target HN, this requires closer inspection. With older templates, simply moving over the templates would be the end of it- you see the version listed when you do a vzplgls:

mysql-rh9 20030814 20050412

this means there are 2 versions of the mysql package for RH9: 20030814 and 20050412 As an aside, you can't copy over just 1 of them, but if you rsync'd over the mysql-rh9 directory, you'd see 20030814 and 20050412 on the target HN. As long as the versions match up, you're good to go.

With EZ templates, the versions are not as easy to decipher. When you look at the vzpkg list output, that simply tells you when a cache was created. A cache is simply a snapshot of all the data needed for the latest versions of the OS and it's applications at the time the cache was created. It is a date, and thus tells you nothing about the versions within. So for instance, if you had a cache for Ubuntu 10.04 from 2007 and you ran vzpkg create cache ubuntu-10.04-x86 it would re-download the latest version of apache, mysql and so on. And any subsequent ubuntu 10.04 CT's created thereafter would use those newer versions, whereas older CT's based on 10.04 would use older templates. You can see how this works by looking at the files under:

# ls /vz/template/ubuntu/10.04/x86/
aap_1.091-1_all
aap-doc_1.091-1_all
adduser_3.112ubuntu1_all
anacron_2.3-13.1ubuntu11_i386
apache2_2.2.14-5ubuntu8.2_i386
apache2_2.2.14-5ubuntu8.4_i386
apache2_2.2.14-5ubuntu8.6_i386
apache2_2.2.14-5ubuntu8.7_i386
apache2_2.2.14-5ubuntu8.8_i386
apache2_2.2.14-5ubuntu8.9_i386
<...snip>

You can see that this template has in it 6 different versions of apache2. This means that this template was merged with other 10.04 templates and/or it has been cached a few times, each time a new apache was available. The unfortunate thing is it's almost impossible to know which CT's are using which version of apache so it's hard to try to prune this down and remove unwanted/unneeded applications.

So, if you see another HN has Ubuntu 10.04 on it, you need to see/confirm that it has all the exact files your CT needs. You can run a test rsync to see what would be transferred (what's missing):

rsync -avn --stats -e ssh /vz/template/ubuntu/10.04 root@10.1.4.69:/vz/template/ubuntu

Based on the amount of data you get back from the rsync, you will be able to decide whether or not to remove the -n and allow the full transfer to go through. The downside to doing the transfer is the situation described above- you've permanently joined these templates and now you may have 10 versions of apache on the target HN. There's one other potential pitfall to this kind of merging- it will also potentially copy over shared files, for which there is no particular version, most of which are in /vz/template/ubuntu/10.04/x86/config:

cat /vz/template/ubuntu/10.04/x86/config/os/default/repositories
/vz/template/ubuntu/10.04/x86/config/os/default/repositories

Here are some specific things to look out for. Case: copying centos-5 on virt19 to virt12. We dumped the rsync output to a file so we could inspect:

[root@virt19 /vz/template]# rsync -an -e ssh /vz/template/centos/ root@10.1.4.62:/vz/template/centos/ > v12_c5

(note, that can be dangerous, better to add on full path /vz/template/centos/5)

So in the output file we see things like:

x86/base0/cachecookie
x86/base0/primary.xml.gz 
x86/base0/primary.xml.gz.sqlite 
x86/base0/repomd.xml 
x86/base1/cachecookie 
x86/base1/filelists.xml.gz 
x86/base1/filelists.xml.gz.sqlite  
x86/base1/primary.xml.gz 
x86/base1/primary.xml.gz.sqlite 
x86/base1/repomd.xml
x86/base2/cachecookie

Which make us nervous cause those are not versioned files, i.e.:

5/x86/MAKEDEV-3.23-1.2.i386/usr/sbin/mksock

So those files will replace existing files on v12 rather than the case of the latter where it's likely being added. So caution should be given and deference to whichever version is newer (which rsync should take care of, but that will depend on the date each file was created and perhaps not the actual data within).

If we look further in the file we see:

x86/psa-appvault-moodle-1.8-8202920080409011254.noarch/usr/local/psa/var/cgitory/moodle-1.

9/htdocs/lib/editor/htmlarea/plugins/TableOperations/img/cell-split.gif

and other files looking like:

5/x86/plesk-base-9.0.1-cos5.build90090127.18.i586/etc/sw/keys/info

Which means plesk is here. We don't need plesk on v12 (the CT moving over doesn't use it) so we rerun the rsync and exclude it:

[root@virt19 /vz/template]# rsync -an -e ssh --exclude="plesk*" --exclude="psa*" /vz/template/centos/ root@10.1.4.62:/vz/template/centos/ > v12_c5

and now it's much smaller:

[root@virt19 /vz/template]# cat v12_c5|wc -l
97104

Before running with excludes it was:

[root@virt19 /vz/template]# cat v12_c5|wc -l 
238238

So again, look at what you're doing. Generally, combining templates is fine however.

If you're happy with the merge, run the rsync again without the "-n" to let it actually do the transfer.

Once done, don't forget to add the new template to the HN in Management -> Reference -> Templates