Re: [libvirt] [RFC PATCH 0/8 v3] Summary on block IO throttle
On 11/10/2011 02:50 PM, Adam Litke wrote:
Hi Lei,
I've tested this and found that it works well except for one small thing.
When the domain is running and I change one of the throttle settings using the
--config option in virsh, the on-disk domain xml file is properly updated, but
the command 'virsh dumpxml' returns the old version. Is this how it is supposed
to work?
Yes:
virsh blkdeviotune --config => on-disk only (takes effect next boot;
fails if transient)
virsh blkdeviotune --live => running only (takes effect now, and lost on
next boot; fails if offline persistent)
virsh blkdeviotune --config --live => on-disk and current (takes effect
now and persists to next boot; fails if not running persistent)
virsh blkdeviotune --current => either --config or --live
Also, in thinking about this, I can't help wonder if for extensibility
of ALL the virTypedParameter commands, we might be better off with
exposing a long-hand option for raw control of virTypedParameter, so
that an older virsh can still set options in a newer server without
having to recompile virsh to add a new named option to match every new
hypervisor named option. Something like:
virsh blkdeviotune --set-long total_bytes_sec=number
as long-hand for:
virsh blkdeviotune --total_bytes_sec number
We still need a v4 respinning this to use virTypedParameter; I can help
by posting a patch 1/8 that shows the changes that I think we need in
the public interface, but I don't want to spend the time rebasing the
entire series.
--
Eric Blake eblake(a)redhat.com +1-801-349-2682
Libvirt virtualization library http://libvirt.org