[libvirt-users] Problem executing VM backups

[Markus Ellinger]

Hello,

thank you very much for your suggestions. I changed our backup script to 
use the method explained in 
http://wiki.libvirt.org/page/Live-disk-backup-with-active-blockcommit 
and this night, everything seems to have worked smoothly. The backup is 
even faster now than before.

Best regards
Markus

Am 22.06.2016 um 19:16 schrieb Kashyap Chamarthy:
> On Wed, Jun 22, 2016 at 08:59:24AM +0200, Markus Ellinger wrote:
>> Hi everyone,
>>
>> we are suddenly having a problem with executing our backup jobs. For a long
>> time, we have used a shell script which contains the following code to
>> backup all our virtual machines:
>>
>>          for domain in Testserver Faktura Fileserver Gitolite Jenkins Nexus
>> SimpleHelp VpnGateway Wiki; do
>>                  echo -n "$(date +"%Y-%m-%d %H:%M:%S") starting backup for vm
>> ${domain} ... " >> ${vmlog}
>>                  virsh dumpxml --security-info ${domain} >
>> ${vmdir}/${domain}.xml
>>                  virsh undefine ${domain}  >> ${vmlog}
>>                  virsh blockcopy ${domain}
>> /var/lib/libvirt/images/${domain}.img ${vmdir}/${domain}.img --wait --finish
>>>> ${vmlog}
>>                  virsh define ${vmdir}/${domain}.xml >> ${vmlog}
>>          done
>   
> [...]
>
>>                   root at gfii-host:~# virsh undefine Gitolite
>>                   error: Failed to undefine domain Gitolite
>>                   error: Requested operation is not valid: cannot undefine
>> transient domain
>>
>>                   root at gfii-host:~# virsh blockcopy Gitolite
>> /var/lib/libvirt/images/Gitolite.img /tmp/test-blockcopy-gitolite.img --wait
>> --finish
>>                   error: block copy still active: disk 'vda' already in
>> active block job
>>
>>                   root at gfii-host:~# virsh blockjob Gitolite
>> /var/lib/libvirt/images/Gitolite.img
>>                   No current block job for
>> /var/lib/libvirt/images/Gitolite.img
> I was going to suggest that in the even if you do see an active block
> job here, then you could've aborted it via:
>
>      $ virsh blockjob Gitolite /path/to/disk/ --abort
>
> But you say there's no active block operation.
>
> (I doubt it will help, but you might want to supply "--info" to that
> `virsh blockjob` query.  From the manual: "In --info mode, the active
> job information on the specified disk will be printed.")
>
>>                   root at gfii-host:~# virsh define
>> /var/local/backup/vms/2016-06-22T013001/Gitolite.xml
>>                   error: Failed to define domain from
>> /var/local/backup/vms/2016-06-22T013001/Gitolite.xml
>>                   error: block copy still active: domain has active block job
> Although I've seen some bug reports (and were fixed) in the past of this
> error during different block operations, but I can't pin-point the exact
> reason here why you're seeing it.
>
> You might want to enable libvirt logging filters (in
> /etc/libvirt/libvirtd.conf) to get some more useful details:
>
>      log_filters="1:libvirt 1:qemu 1:conf 1:security 3:event 3:json 3:file 3:object 1:util"
>      log_outputs="1:file:/var/log/libvirt/libvirtd.log"
>
> (Don't forget to restart libvirt daemon before performing your test.)
>
>
> While we're at it, here's another another way to perform live backups
> (which is slightly more efficient), if it is of any help:
>
>      http://wiki.libvirt.org/page/Live-disk-backup-with-active-blockcommit
>
>> Of course we tried to start/stop the virtual machines, rebooted the whole
>> host multiple times etc., but the problem comes back every night.
>>
>> The machine is a Debian Wheezy machine with current updates. We are using
>> the qemu-kvm package from wheezy-backports to enable blockcopy support.
> Specifying explicit versions will be convenient.
>
>   
>

-- 
Dipl.-Inf. Markus Ellinger
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fax +49-911-148780-44
email ellinger at gfii.de

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