5:17 a.m.
Hi,
virsh has save/restore to do a one-time save+shutdown. But it
does not expose kvm's savevm/restorevm, which let's me do
incremental snapshots. Is there a specific reason why that
is not exposed in libvirt, or is it just that noone has
implemented it?
thanks,
-serge
5:32 a.m.
On Tue, Jul 20, 2010 at 05:17:43AM -0500, Serge Hallyn wrote:
Hi,
virsh has save/restore to do a one-time save+shutdown. But it
does not expose kvm's savevm/restorevm, which let's me do
incremental snapshots. Is there a specific reason why that
is not exposed in libvirt, or is it just that noone has
implemented it?
This is included in the 'snapshot' APIs / virsh commands as of 0.8.1
libvirt release
Daniel
--
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9:24 a.m.
Quoting Daniel P. Berrange (berrange(a)redhat.com):
On Tue, Jul 20, 2010 at 05:17:43AM -0500, Serge Hallyn wrote:
> Hi,
>
> virsh has save/restore to do a one-time save+shutdown. But it
> does not expose kvm's savevm/restorevm, which let's me do
> incremental snapshots. Is there a specific reason why that
> is not exposed in libvirt, or is it just that noone has
> implemented it?
This is included in the 'snapshot' APIs / virsh commands as of 0.8.1
libvirt release
Oh, excellent! (Alas, my libvirt 0.8.1 doesn't seem to think that
my qcow2 images can support snapshots, but I"ll have to look into
that some more)
thanks,
-serge
9:59 a.m.
On 07/20/2010 04:24 PM, Serge Hallyn wrote:
Quoting Daniel P. Berrange (berrange(a)redhat.com):
> On Tue, Jul 20, 2010 at 05:17:43AM -0500, Serge Hallyn wrote:
>
>> Hi,
>>
>> virsh has save/restore to do a one-time save+shutdown. But it
>> does not expose kvm's savevm/restorevm, which let's me do
>> incremental snapshots. Is there a specific reason why that
>> is not exposed in libvirt, or is it just that noone has
>> implemented it?
>>
> This is included in the 'snapshot' APIs / virsh commands as of 0.8.1
> libvirt release
>
Oh, excellent! (Alas, my libvirt 0.8.1 doesn't seem to think that
my qcow2 images can support snapshots, but I"ll have to look into
that some more)
You will need to set the driver type <driver name='qemu'
type='qcow2'/>
example:
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2' cache='writethrough'/>
<source file='/var/lib/vm/data/images/debian.img'/>
<target dev='vda' bus='virtio'/>
</disk>
Regards,
Jason
3:29 p.m.
Quoting Jason Krieg (jason.krieg(a)collax.com):
On 07/20/2010 04:24 PM, Serge Hallyn wrote:
>Quoting Daniel P. Berrange (berrange(a)redhat.com):
>>On Tue, Jul 20, 2010 at 05:17:43AM -0500, Serge Hallyn wrote:
>>>Hi,
>>>
>>>virsh has save/restore to do a one-time save+shutdown. But it
>>>does not expose kvm's savevm/restorevm, which let's me do
>>>incremental snapshots. Is there a specific reason why that
>>>is not exposed in libvirt, or is it just that noone has
>>>implemented it?
>>This is included in the 'snapshot' APIs / virsh commands as of 0.8.1
>>libvirt release
>Oh, excellent! (Alas, my libvirt 0.8.1 doesn't seem to think that
>my qcow2 images can support snapshots, but I"ll have to look into
>that some more)
>
You will need to set the driver type <driver name='qemu'
type='qcow2'/>
example:
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2' cache='writethrough'/>
<source file='/var/lib/vm/data/images/debian.img'/>
<target dev='vda' bus='virtio'/>
</disk>
Regards,
Jason
Thanks! That worked beautifully. Well, interestingly, the
first time I made this change, the '<driver name=' line got
cut off so the type and cache options were gone, but once it
let those stick, it worked great.
thanks!
-serge
8:11 a.m.
On 07/20/10 - 05:17:43AM, Serge Hallyn wrote:
Hi,
virsh has save/restore to do a one-time save+shutdown. But it
does not expose kvm's savevm/restorevm, which let's me do
incremental snapshots. Is there a specific reason why that
is not exposed in libvirt, or is it just that noone has
implemented it?
The save/restore API only does a memory snapshot. If you are referring
to the savevm/loadvm/delvm, which take a disk+memory snapshot, then that is
implemented in terms of the libvirt snapshot API. You can start here:
http://libvirt.org/html/libvirt-libvirt.html#virDomainSnapshotCreateXML
--
Chris Lalancette
10:40 a.m.
Quoting Chris Lalancette (clalance(a)redhat.com):
On 07/20/10 - 05:17:43AM, Serge Hallyn wrote:
> Hi,
>
> virsh has save/restore to do a one-time save+shutdown. But it
> does not expose kvm's savevm/restorevm, which let's me do
> incremental snapshots. Is there a specific reason why that
> is not exposed in libvirt, or is it just that noone has
> implemented it?
The save/restore API only does a memory snapshot. If you are referring
Jinkeys, I guess so - my first tests were confounded by the page
cache being reverted and then synced back to disk :)
to the savevm/loadvm/delvm, which take a disk+memory snapshot, then
that is
implemented in terms of the libvirt snapshot API. You can start here:
http://libvirt.org/html/libvirt-libvirt.html#virDomainSnapshotCreateXML
Ok, so the snapshot created by virDomainSnapshotCreateXML is not what
is used by 'virsh snapshot-create'? Are there any plans of exporting
this through virsh?
thanks,
-serge
12:13 p.m.
On 07/22/10 - 10:40:44AM, Serge Hallyn wrote:
Quoting Chris Lalancette (clalance(a)redhat.com):
> On 07/20/10 - 05:17:43AM, Serge Hallyn wrote:
> > Hi,
> >
> > virsh has save/restore to do a one-time save+shutdown. But it
> > does not expose kvm's savevm/restorevm, which let's me do
> > incremental snapshots. Is there a specific reason why that
> > is not exposed in libvirt, or is it just that noone has
> > implemented it?
>
> The save/restore API only does a memory snapshot. If you are referring
Jinkeys, I guess so - my first tests were confounded by the page
cache being reverted and then synced back to disk :)
> to the savevm/loadvm/delvm, which take a disk+memory snapshot, then that is
> implemented in terms of the libvirt snapshot API. You can start here:
>
> http://libvirt.org/html/libvirt-libvirt.html#virDomainSnapshotCreateXML
Ok, so the snapshot created by virDomainSnapshotCreateXML is not what
is used by 'virsh snapshot-create'? Are there any plans of exporting
this through virsh?
No, these two things are the same; virsh snapshot-create calls
virDomainSnapshotCreateXML (which eventually calls savevm in the qemu monitor).
--
Chris Lalancette
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7 comments
4 participants
participants (4)
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Chris Lalancette -
Daniel P. Berrange -
Jason Krieg -
Serge Hallyn