Monday, October 4, 2010

Windows Server Backup - MS gives you less

I have a dream. One where I can backup a server with minimal fuss, with desirable and delicious features like backing up locked files, storing multiple points in time, only backing up changed sectors, and having a command line tool to control jobs.

Believe it or not, there are tons of vendors out there selling backup software that recopies entire files when only a few bytes have changed. So with VM images, this could mean tens of GBs of unnecessary data copies every time you do a backup. Kind of a bummer.

Anyone who's tried to run ntbackup.exe in Server 2008 has discovered the buried, curious, new tool called Windows Server Backup. Maybe this is what we were looking for all along? Maybe not.

Great stuff that MS removed since ntbackup.exe:

  • Backup to tape -- no longer supported, you need a 3rd party backup program to do this
  • Backup to network (CIFS) share -- no longer offered, see note below

A work around for the network share feature is to use the wbadmin.exe tool to manually execute backups to network destinations with the huge limitation that it will completely overwrite the previous backup that was stored there. So for 1TB of data, you are copying 1TB each day!

Other "features"

  • If you select a complete system backup (suitable for bare-metal restore), then all drives on my server are selected because Windows thinks that there are system files on my E:\ drive. But Server Backup won't tell you what/where they are!

Luckily, there are a few bits of candy that Microsoft is going to tease you with:

  • VHD format backups
  • VSS support for getting data in a consistent state (Hyper-V and SQL Server)
  • It's free with Windows Server

I'm a nerd, and I get nerd-fanciful about the fact that VHD is the new backup format. I could conceivably use qemu-img to convert the VHD files to a raw disk image suitable to dd to a new server from a Linux live CD. Seeing as it's used in Hyper-V as well, I can see a lot of 3rd party developers offering tools to recover data from VHDs in the event of corruption.

Having said all of this, the About dialogue shows Windows Server Backup @ v1.0, so maybe all this will be fixed the next time around. How about you? Have you found the perfect backup tool that has the features mentioned at the top of the article?

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