[libvirt] vm snapshot multi-disk

Chun Yan Liu cyliu at suse.com
Thu Jul 16 02:26:14 UTC 2015



>>> On 7/14/2015 at 05:42 AM, in message
<CALFpzo551ioR=w5ASF7JXmtP8EgQSP2au_O6awmyofz9MfG3vg at mail.gmail.com>, Marcus
<shadowsor at gmail.com> wrote: 
> Oh, I almost forgot to mention the versions: 
>  
> libvirt 1.2.8-16.0.1.el7_1.2.x86_64 
>  
> qemu 2.1.2-23.el7_1.1.x86_64

Just FYI, tested on my machine, libvirt 1.2.5, qemu 2.0.0, didn't see this problem.
Both disk snapshots are deleted.

>  
>  
> Also, I'm unclear if the domain snapshot feature is orchestralted by 
> libvirt, or something that is simply called into qemu to take care of. 
> Please forgive me if this is a qemu issue. 
>  
> On Mon, Jul 13, 2015 at 2:35 PM, Marcus <shadowsor at gmail.com> wrote: 
>  
> > Hi all, 
> > 
> >     I've recently been toying with VM snapshots, and have ran into an 
> > issue. Given a VM with multiple disks, it seems a snapshot-create followed 
> > by a snapshot-delete will only remove the qcow2 snapshot for the first disk 
> > (or perhaps just the disk that contains the memory), not all of the disk 
> > snapshots it created. Is this something people are aware of? 
> > 
> >     In searching around, I found a bug report where snapshot-creates would 
> > fail due to the qcow2 snapshot ids being inconsistent. That looks like it 
> > is patched for 2.4 qemu ( 
> > http://lists.nongnu.org/archive/html/qemu-devel/2015-03/msg04963.html), 
> > this bug would trigger that one by leaving IDs around that are inconsistent 
> > between member disks, but is not the same. 
> > 
> > # virsh snapshot-create 7 
> > 
> > Domain snapshot 1436792720 created 
> > 
> > 
> > # virsh snapshot-list 7 
> > 
> >  Name                 Creation Time             State 
> > 
> > ------------------------------------------------------------ 
> > 
> >  1436792720           2015-07-13 06:05:20 -0700 running 
> > 
> > 
> > # virsh domblklist 7 
> > 
> > Target     Source 
> > 
> > ------------------------------------------------ 
> > 
> > vda 
> >  
> /mnt/2a270ef3-f389-37a4-942f-380bed9f70aa/e4d6e885-1382-40bc-890b-ad9c8b51a7a 
> 5 
> > 
> > vdb 
> >  
> /mnt/2a270ef3-f389-37a4-942f-380bed9f70aa/7033e4c6-5f59-4325-b7e0-ae191e12e86 
> c 
> > 
> > 
> > # qemu-img snapshot -l 
> >  
> /mnt/2a270ef3-f389-37a4-942f-380bed9f70aa/e4d6e885-1382-40bc-890b-ad9c8b51a7a 
> 5 
> > 
> > Snapshot list: 
> > 
> > ID        TAG                 VM SIZE                DATE       VM CLOCK 
> > 
> > 1         1436792720             173M 2015-07-13 06:05:20   00:01:10.938 
> > 
> > 
> > # qemu-img snapshot -l 
> >  
> /mnt/2a270ef3-f389-37a4-942f-380bed9f70aa/7033e4c6-5f59-4325-b7e0-ae191e12e86 
> c 
> > 
> > Snapshot list: 
> > 
> > ID        TAG                 VM SIZE                DATE       VM CLOCK 
> > 
> > 1         1436792720                0 2015-07-13 06:05:20   00:01:10.938 
> > 
> > 
> > # virsh snapshot-delete 7 1436792720 
> > 
> > Domain snapshot 1436792720 deleted 
> > 
> > 
> > # qemu-img snapshot -l 
> >  
> /mnt/2a270ef3-f389-37a4-942f-380bed9f70aa/e4d6e885-1382-40bc-890b-ad9c8b51a7a 
> 5 
> > 
> > # qemu-img snapshot -l 
> >  
> /mnt/2a270ef3-f389-37a4-942f-380bed9f70aa/7033e4c6-5f59-4325-b7e0-ae191e12e86 
> c 
> > 
> > Snapshot list: 
> > 
> > ID        TAG                 VM SIZE                DATE       VM CLOCK 
> > 
> > 1         1436792720                0 2015-07-13 06:05:20   00:01:10.938 
> > 
>  





More information about the libvir-list mailing list