Re: [Xen-users] Backup domU image at runtime

[Simon Hobson <linux@xxxxxxxxxxxxxxxx>]

Alberto Asuero wrote:

> And how could I make a backup of a whole domU at runtime? is that possible?
You would have to pause the DomU and image both it's disk(s) image(s) 
**AND** it's current state. In the event of restoring such a backup, 
you'd kill the guest, restore the image, and unpause the restored 
image - the guest would continue from the exact state it was in when 
it was paused before the backup.
Your only easy option with this type of backup is to restore the 
entire machine & state to a point in time. It's hard to retrieve a 
single file - you'd need to restore the whole virtual machine to a 
temporary location, unpause it without letting it connect to the live 
network, pull the files you want, and then destroy it.
> Now what I'm doing is backing up the files of domU with rdiff-backup 
> but I'd like a system that allow to restore a domU quickly (now I've 
> to reinstall the whole SO and restore the files and applications)
I use Rsync from within each guest to back their entire filesystems 
to a shared space. From there I use StoreBackup to make multiple 
generations.
In a recovery situation, I can restore any individual machine to it's 
last backup with the following steps :
In Dom0, create the LVM volumes, create filesystems, mount them.
Rsync the files back from the shared backup space.
Unmount the volumes from Dom0
Startup the guest.

If I've had to move the guests (eg host gone tits-up), then I can 
pull the guest config files from the backup space (hosts are backed 
up here as well) to another host.
That's only one wya of doing it.


If I need to access an old version of a file, then that can be pulled 
from the StoreBackup archives.
--
Simon Hobson

Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
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