[Qemu-devel] Re: KVM call agenda for Mar 16

[Anthony Liguori <anthony@codemonkey.ws>]

On 03/16/2010 10:23 AM, Daniel P. Berrange wrote:
> In the context of the RHEV management application, iSCSI/SCSI Fibre are
> providing the raw storage, with LVM VGs on top and the carving LVs for
> the guests. In the common case the admin/app would monitor VG usage&  LV
> rate of increase to ensure extra space was available in the VG ahead of
> it being needed. eg if the VG comes close to exhaustion then further LUNS
> can be obtained and added as PVs to the LVM volume group. So you can't
> guarentee that a VM won't stop on ENOSPC, but it is very unlikely if the
> system is operating correctly.
>
> As an added complication, since cluster-LVM isn't used, all LVM operations
> have to be performed on a dedicated/exclusive storage host and then metadata
> refreshed/propagated to other hosts running VMs. This last issue implies that
> letting QEMU resize its LV would never be possible, even if it were not for
> the permissions problem.
>    

Sounds like a good argument for polling :-)

Regards,

Anthony Liguori

> Regards,
> Daniel
>