[libvirt-users] Incremental Backups

[Daniel Berteaud]

Le vendredi 20 septembre 2013 à 15:31 +0200, Thomas Stein a écrit :
> Hello.
> 
> Is someone performing incremental backups via libvirt for qemu/kvm 
> machines? I'm still having a hard time to
> find a nice procedure. I mean is it possible to make a full backup of an 
> image on monday a do the next days of the week
> incremental backups?

You can take a look at this script:
http://gitweb.firewall-services.com/?p=virt-backup;a=blob_plain;f=virt-backup;hb=HEAD

I'm using it on several servers. You can either take a full backup (raw
dd of your LV), or incremential backups. Incrementials are done this
way:

- pause the VM
- take an LVM snapshot of each of its disk
- resume the VM
- use chunkfs to mount the LVM snapshots as if it was a lot of small
files
- now you can rsync the fuse mount point using rsync, and only modified
blocks will be transfered. If you use something like BackupPC or
rsnapshot, it'll also only store on disk the modified blocks


Regards, Daniel
> 
> Another way could be mount the image and rsync its contents. Does that 
> makes sense?
> 
> Also i read in qemu changelog:
> 
> ---
> Support for a new block device background job. Started by drive-backup, 
> it will backup a disk's content to a new file. Unlike drive-mirror, the 
> new file will include the source disk's content at the time the backup 
> job was started. Atomic backup of multiple disks is supported using the 
> "transaction" QMP command.
> ---
> 
> Is this supported by libvirt?
> 
> thanks and best regards
> thomas
> 
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-- 
Daniel Berteaud
FIREWALL-SERVICES SARL.
Société de Services en Logiciels Libres
Technopôle Montesquieu
33650 MARTILLAC
Tel : 05 56 64 15 32
Fax : 05 56 64 15 32
Web : http://www.firewall-services.com