On 7/10/07, Richard W.M. Jones <rjones@redhat.com> wrote:

Omer Khalid wrote:
> Hi,
>
> I am wondering if its possible to upgrade an existing libvirt
> installation to a newer version. Actually one of my clients is still
> have libvirt-0.1.8 while my software works ver 0.1.9 upwards.

As Dan said, ABI compatibility should be maintained, pretty much
forever.  I guess if we ever did break it, there would be a major jump
in version number (like 1.x -> 2.x or similar).

Another issue is that upgrades between versions require different
daemons running.  In < 0.2.0 there was no daemon at all.  In < 0.3.0 the
daemon was called libvirt_qemud (unless you were also playing with the
experimental remote patches, in which case you may have needed two
daemons running).  In >= 0.3.0 the daemon is called libvirtd and
combines the functions of qemu management, network management and remote
access all in one handy package.  So when upgrading between versions,
bear this in mind.  Restarting the libvirt service should be sufficient,
but if that doesn't work there is a small possibility you might need to
reboot.

Also we are maintaining a list of what features work with what
hypervisor in what version.  You can find that here:
http://libvirt.org/hvsupport.html

Rich.

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