[fedora-virt] handling guest-service dependencies at boot time elegantly?

[Richard W.M. Jones]

On Thu, Jun 11, 2009 at 03:38:30PM -0400, Bill McGonigle wrote:
>  xm create nexenta
>  [watch xentop to see when it's running]
>  service iscsi start
>  service xendomains start
>
> Which works find and requires me to do it.  I can write some scripts to  
> do the same thing, but if there was a more general-purpose way to  
> express these kinds of boot-time dependencies, I'd rather do it right.
>
> I was thinking perhaps upstart could be co-opted for this purpose, if I  
> can make it not cobbler init (it would have to run alongside on 5.3).  
> Are there any libvirt event hooks into upstart?

Common problem, no good solutions.

The best advice I think is to change your architecture so that virtual
machines can cope with other services being unavailable.  Not just at
boot time, but _any_ time, because you never know when you might need
to restart your iscsi service.

NFS can do this with background mounts and so on.  I'm not sure about
iscsi though ...

Rich.

-- 
Richard Jones, Emerging Technologies, Red Hat  http://et.redhat.com/~rjones
virt-p2v converts physical machines to virtual machines.  Boot with a
live CD or over the network (PXE) and turn machines into Xen guests.
http://et.redhat.com/~rjones/virt-p2v