Backups for VMs

[sparkeh]

So I have got my head into a bit of a mess over the best way to back up my VMs.

 

At this this site there is currently one physical machine running two VMs (Server 2008 R2 and Server 2003). At the moment each VM uses ntbackup to back up to a NAS box and I use the Hyper-V manager to take snapshots. The idea being that if something goes wrong with a VM I can either restore from ntbackup or revert to a snapshot. If something goes wrong with the physical server I can run another machine up with Hyper-V and attach the saved disk images and be up and running again.

That works right?

 

However, as ntbackup is failing on one the machines with the inconsistency error on verification (for which I can find no cure for) I thought I would look at alternatives.

 

I have looked at Acronis and see that there is a virtual addition of the server backup product and an add on for bare metal restores. I have also look at Backexec but can't make head nor tails of which of their products I need.

 

Is there any advantage of spending money on Acronis/Backupexec for VMs or is the way I am doing it above suitable?

 

Cheers.

[vikpaw]

Just been talking on this thread which may have some insight for you. Also some users of Acronis you could talk to.

http://www.edugeek.net/forums/how-do-you-do/50618-virtualisation-tutorial.html

 

I would say snapshots are good, but they are part of your VM, so you need fault tolerance on your VMs.

 

I think you're saying your ntbackup is backing up the VM as in from the running OS. I would say it's worth backing up the actual VM file itself to another box. This would be useful if the host server died, and you needed to create a new one. the backup of the VM file in itself is overkill as you're backing up files that don't change, so it's best to still have some kind of file backup as you would with a regular physical server.

 

Or, have i completely misunderstood your setup...?

[sparkeh]

Thanks Vik,

Yeah I think you got it.

 

I am running ntbackup from within the OS of each VM, just as if it were a physical machine and the VM files are being copied from the host machine to backup storage.

 

What I am mulling over is if the worst case happens, and the physical machine dies, and I can create a new Hyper-V server and start the VMs on that, is there any advantage to third party backup software?

[vikpaw]

i don't think so.

 

imagine that your are storing your vm files on a separate area be it nas/san etc. you can have 2 identical host servers set up for virtualisation and point either at your vm files. if one bit of hardware dies, switch to the backup.

 

how you back up those vm files is a slightly different issue and down to preference. it's probably worth someone who has been doing this for a while to volunteer their different approaches.

 

i can't see what a third party product adds. if your storage has fault tolerance and you have some kind of backup albeit slow, that should be enough.

 

but, there are too many factors, what are you running on VM? how important is it? how quick do you need to recover? how often does the data change? do you want to back up to tape another medium offsite....?

[adamchapman]

i don't think so.

 

imagine that your are storing your vm files on a separate area be it nas/san etc. you can have 2 identical host servers set up for virtualisation and point either at your vm files. if one bit of hardware dies, switch to the backup.

 

i can't see what a third party product adds. if your storage has fault tolerance and you have some kind of backup albeit slow, that should be enough.

QUOTE]

 

I found an iomega NAS box that auto replicates with another iomega NAS box for resillience... so you've always got two identical NAS boxes if one dies... that way the data is safe. Thought it would be a good idea and a good place to start for virtualisation (when I get around to it!!)

[Ric_]

@adamchapman: That's what I do but with Sun Storage 7110s - the two boxes sit in different buildings. I also do nightly backups to tape in the old fashioned way using retrospect

 

You can usually select an alternative storage area for your snapshots too... if you can snapshot to a remote iSCSI box, that's another option.

 

A word of caution... don't be snapshotting DCs - BAD things happen if you roll them back! See Considerations when hosting Active Directory domain controller in virtual hosting environments