[Sheepdog] Backup/Images

[Frank Matthieß]

Hello Mark,

[Mark Pace, Freitag 07 Oktober 2011 06:30]:
> Hello everyone.  I've been following the development and have been
> testing sheepdog in a limited environment.  My key concerns (beyond
> stability) revolve around offline/offsite backing up.  I'd like to
> achieve the following somehow, albeit with built in sheepdog
> functions or functions that are pushed into qemu-img.
> 
>  1. Offline backups:  Right now sheepdog offers redundancy, but there
>     needs to be a way to store consistent offline backups.  Being
> able to have a node that stored complete copies of images that could
> then be copied from that location would be ideal.  For example,
> could a special node would participate in the cluster as a mechanism
> for making backups?  You could go to this node and see the current
> copy of each image (regardless of how many copies you configured,
> this node would have complete copies of every stored virtual).  You
> could then use file system snapshotting to make copies of these
> files for offline/offsite/cloud storage

From my view it would be enough to get snapshots from the images, which 
can be copied to a backup media. 

The problem here is to get a *consitend* snapshop from the guest os 
view. This is the hard part. 


>  2. Images/snapshots to files: a mechanism to take a snapshot or a
>     regular image out of the sheepdog cluster to turn it into a file
> for backup, to be sent to a customer, stored on a hard drive, etc. 
> This may already exist in qemu-img, but I don't know how easy it is
> to take a snap and turn it into a full image.  This is more of a one
> off thing than the first point, but is necessary none-the-less.  I
> see that qcow2 images can be created from snapshots using a
> relatively new (or a least the site I read claimed it was relatively
> new) feature of the qemu-img convert functionality -- does sheepdog
> also support this?

At least from version 0.2.4, which is released yesterday, the collie 
command will give you the ability to read and write to sheepdog 
blockstorage.

Backup:
# collie vdi snapshot VolumeName -s BackupVolumeName
# collie vdi read VolumeName -s BackupVolumeName > BackupFile

will do the job.

Frank.
-- 
Frank Matthieß                               Mail f4m8at at googlemail.com
                                             G+    http://gplus.to/fmat