[CentOS-virt] guest management: 1 and only 1 instance

Fri Feb 26 08:12:29 UTC 2010
Christopher G. Stach II <cgs at ldsys.net>

----- "Christopher Hunt" <dharmachris at gmail.com> wrote:

> Gang,
>      I run several KVM host machines.  Due to updates, maintenance,
> and unexpected reboots sometime host machines are restarted.  I can
> easily envision a scenario where HostX needs some critical packages
> updated or is acting up.  I migrate guest0, guest1, guest2 etc. from
> HostX to HostY.  Then, in either a planned (i.e. scheduled
> maintenance) or unplanned (i.e. unplanned reboot) event reboots
> HostX.
>  Unfortunately guest0, guest1 and guest2 are all set to autostart on
> HostX but they're currently running on HostY when HostX boots.... etc
> etc etc
> 
>     Is anyone using effective packages, scripts or techniques which
> help maintain that all guest are running once and only once across a
> cluster of KVM hosts?  I have been using virt-manager but it's not
> automated so much...

Red Hat Cluster Suite
Heartbeat
etc.

Or, if you want to roll your own, just run a MySQL instance or two, use SERIALIZABLE isolation, poll guest lists with ``xm info'' or whatever you want, store the info in MySQL, etc. Should take about an hour if you start from scratch. It's easier with other DBs, or even files and lockfiles, but it really depends on your experience. If you're asking this, something SQL is probably the easiest. Heck, just do it in bash, cron, and ssh.

-- 
Christopher G. Stach II
http://ldsys.net/~cgs/