How I Backup Virtual Machines Locally and to Another Server

I did some searching on the internet and found a couple of scripts to backup VMs.

We use Hyper-V and VMware on our server farm but because we are an educational institution we don’t have much money to invest in sophisticated stuff (well they seem to have money left over for other things that are debatable 😉

Anyways, so I tried the scripts but all those VB or batch file scripts require the machine to be put to sleep or switched off. Since we needed real backups without turning anything off that didn’t help much.

I kept browsing and found this interesting article How to Backup Virtual Machines While Running  and set it up.

Interestingly this tool also backs up SQL Server databases using the same principles. It unlocks the files while in use and copies them somewhere else. Unlike the scripts, however, it doesn’t need to pause the VMs and uses delta compression to write incremental files. I recall from my early unix days the rsync utility. It appears it’s pretty much a similar thing because it creates a  ‘delta’ file with the changes in the VM that it found since the previous day’s backup.

Sending it off to another server: we tried two things which both worked. We have another server location where we access the network shares on the WAN. The BackupChain utility also comes with a FTP server to send and receive backups but I didn’t need bother it because the delta was all I needed. We run backups at night and are left with about 2 to 10% file changes per day, which in our case brings the backup down to just a couple GB per day on average.

Because I’m a big fan of external hard drives I prefer using this tool to backup to USB. I think we got already our money’s worth because we didn’t have to buy another extra drive. A new 2TB drive still costs about $150 so that won’t be necessary until we add a couple of VMs. However, don’t expect a full blown enterprise-ready monster solution with fancy web interface and all that.

Setting it up took a while, but that seemed to have been caused by my ‘over-optimization’ of the server 😉 Ensure the Volume Shadow Service and all Hyper-V services are enabled. I had the VSS disabled and that didn’t work initially.