Documentation

2008-08-12T13:20:55Z

Fluor: /* Guides and Howtos */

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[[Image:Icon-Caution.png|left]]
We are currently migrating to MediaWiki from our old system, but not all content has been migrated yet. Take a look at the [[Wiki Team]] page for instructions how to help or look at the [http://oldwiki.linux-vserver.org old wiki] to find the information not migrated yet.

'''To ease migration we created a [[List of old Documentation pages]].'''
</div>

== Introduction ==

* [[Overview|Virtualization Overview]]
* [[Usage Scenarios]]
* [[Feature Matrix]]

== Installation ==

* [[Installation Considerations]]
* [[Installation on Linux 2.6]]
* [[Installation on ArchLinux]]
* [[Installation on CentOS]]
* [[Installation on Debian]]
* [[Installation on Fedora]]
* [[Installation on Gentoo]]
* [[Installation on Mandrake]]
* [http://pld-linux.org/Vserver Installation on PLD-Linux]
* [[Installation on Redhat]]
* [[Installation on Slackware]]
* [[Installation on SuSE/OpenSUSE]]
* [[Installation on Ubuntu]]

== Configuration ==

* [[util-vserver:Documentation|util-vserver Documentation]]
* [[vcd:Documentation|VServer Control Daemon Documentation]]
* [[Share a directory among multiple guests]]

== Guides and Howtos ==

* [[Building Guest Systems]]
* [[util-vserver:Howto virtualize an exisiting Linux server|Howto virtualize an existing Linux server]]
* [[VCMD HowTo]]
* [[Howto make bsd-style init sysv-compatible|Howto make Bsd-style init sysv-compatible (archlinux guest system)]]
* [[Installing 32-bit Fedora on 64-bit Debian]]
* [[Installing Ubuntu on Debian]]
* [[Installing an openSUSE vserver guest]]
* [[Networking vserver guests]]
* [[Howto HostAuth]]
* [[Fuse_GlusterFS| Fuse and GlusterFS]]
* [[yum-patch|How to patch vyum]]
* [[yum-upgrade-3.2.4|Upgrading existing installations to yum-3.2.4]]
* [[Migrating from OpenVZ to Linux-Vserver]]

== Lists & Theory ==

* Basic configuration
** [[Capabilities and Flags]]
** [[CPU Scheduler]]
** [[Disk Limits and Quota]]
** [[Resource Limits]]
*** [[Memory Limits]]
** [[Virtual System Information]]
** [[Unification]]

* Security Considerations
** [[Secure Capabilities]]
** [[Secure chroot Barrier]]
** [[Secure Device Nodes]]
** [[Secure ProcFS Entries]]

* Performance and Stability
** [[Virtualization Overhead]]

* Implementation Details
** [[Context Accounting]]
** [[Filesystem Attributes]]
** [[Filesystem Tagging]]
** [[Filesystem Namespaces]]
** [[Kernel Userspace Helper]]
** [[Mainline Kernel Virtualization]]
** [[ProcFS]]
** [[Syscall Command Switch]]

== External Resources ==

Migrating from OpenVZ to Linux-Vserver

2008-08-12T13:19:01Z

Fluor: quick transcript of an openvz to linux-vserver migration

So, you've repeatedely heard that [http://openvz.org/ OpenVZ] was hip, better than [http://linux-vserver.org/ Linux-Vserver] even, and thought you'd give it a try? So did we! However, you weren't as pleased as you were supposed to be, and kept thinking back about how Linux-Vserver was cool for you? Well, if that's your case too, here's how we moved back to Linux-Vserver in a few simple keystrokes.

== System info ==

=== Kernels ===

We are running [http://debian.org/ Debian GNU/Linux], in its testing flavour (pre-release Lenny, frozen package base). For OpenVZ, we were using [http://packages.debian.org/sid/linux-image-2.6.26-1-openvz-686 Debian kernel 2.6.26 with OpenVZ patches]. For Linux-Vserver, we are using [http://packages.debian.org/lenny/linux-image-2.6.25-2-vserver-686 Debian kernel 2.6.25 with Linux-Vserver patches].

=== Paths ===

We created our OpenVZ CTs under ''/srv/vps/$VEID/{private,root}/'', and our vservers under ''/srv/vservers/''.

== Migrating ==

=== Copying data ===

After rebooting under the -vserver kernel, here's how we migrated each VPS, using the 'rsync method':

<pre>
[sudo] vserver $vname build -m rsync \
--hostname $vhostname \
--interface $interface:$ip \
--context $ctx -- \
--source /srv/vps/$veid/private/ -o -va
</pre>

So, for migrating an OpenVZ CT named [http://en.wikipedia.org/wiki/Seitan 'seitan'] using '192.168.66.6' on 'eth0', in context '666', the command would look like:

<pre>
sudo vserver seitan build -m rsync \
--hostname seitan \
--interface eth0:192.168.66.6/24 \
--context 666 -- \
--source /srv/vps/seitan/private/ -o -va
</pre>

Note the trailing ''-o -va'', which allows us to follow rsync as it goes.

=== Fix daemons ===

When rsync is done, we can't start our vservers yet, because some of the system daemons that OpenVZ allows are not compatible with a Vserver environment. Let's remove their startup links, then!

To do so, let's chroot into our freshly migrated vserver:

<pre>sudo chroot /srv/vservers/seitan/</pre>

Once inside, let's unlink all the undesired daemons:

<pre>
for undesired in klogd hwclock.sh setserial urandom networking umountfs halt reboot ;
do update-rc.d -f $undesired remove ;
done
</pre>

=== Enjoy ===

Let's log out of the chroot, and start our vserver!

<pre>
exit
sudo vserver seitan start
</pre>

It should work fine, provided some of your daemons don't depend upon bind mounts from host, which then need to be integrated into the fstab for each of your vservers.

Welcome back!

Linux-VServer - User contributions [en]

Documentation

Migrating from OpenVZ to Linux-Vserver