Re: [Xen-users] Backup domU
On 09/07/2011 08:54, Simon Hobson wrote:
Kalil Costa - Brasilsite wrote:
The backup is also on the same disks as the live system.
I don't know why you make this point, as, at least in this thread, the
target of the backup is not mentioned and is trivial to have it point to
Personally I backup my guests as though they were real (non
virtualised) machines. There are many options for this - both free and
At work I've setup a system where I have a VM dedicated just to
holding backups of the other machines - each of which uses rsync to
update a backup copy of itself on the backup server (the server runs
rsync in server mode). Thus I have a server holding a complete image
of each of my servers at the point they last backed up. Should a host
go down, I can move the guests to another host by creating volumes for
them and using rsync to pull their files back (mount the guest
filesystems on the host, use rsync on the host to pull the files,
unmount the filesystems and start the guest).
Of course, once you are using rsync, then it doesnt' matter whether
the destination is on the same host, another host in the same rack, or
half way round the world - as long as you have enough bandwidth.
On my backup machine I then copy the copies to create various levels
of historical backups. Again there are various ways of doing this, I
settled on StoreBackup which if you disable compression creates full
copies which you can just navigate into and use your normal unix/linux
tools to access files*. It saves space by hard-linking identical files
so it's fairly efficient.
You can do something similar with rsync and some scripting. Another
tool I looked at was rdiff-backup - but I didn't like the way you
can't thin out your backups, and they aren't readable without going
through the restore process.
A perfect tool for this is backuppc. http://backuppc.sourceforge.net/
Quick summary of benefits,
- rsync, smb, ftp support
- uses hardlinks to create incremental backups,
- reduces disk space further by compressing and only storing one copy
of each file across all backups (generates hashes of new files nightly
to determine duplicates)
- We have 29 hosts backed up nightly, with historical backups of some
going back 13 months. Available data in full: 491GB, actual stored
- full set of cmdline tools to manipulate backups
- restore is trivially easy
- web interface gives statistics
- retries failed attempts
- mails you if a machine is not backed up for X hours.
- can give user web access to just their own backups (we don't use
this though, I beleive no web interface is safe)
May the ping be with you ..
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