Tuesday, August 18, 2009

Prepping for Snow Leopard Server and a lesson on backups

We all know that MacOSX 10.6 Server is coming out RSN. All of us who use OpenDirectory are starting to wonder about the pain that will soon endure when upgrading. Here's a few hints to keep in mind.

- Time Machine Backups do not by default restore a good MacOSX Server image. Read all about it here and learn now what will go wrong. Namely, edit the mentioned StdExclusions.plist file to remove /var/log and /var/spool from the exclusion list, and consider recreating your backups from scratch

- If you have ADC membership or otherwise can purchase WWDC 09 videos, acquire Session 622, Moving to Snow Leopard Server. Lots of good stuff there, but I'll suggest a less than perfect but simpler upgrade path

- To upgrade, use Carbon Copy Cloner or the like to make full bootable system copy on an external drive -- likely your time machine disk. At this point, you can also re-enable Time Machine to use the rest of the disk for backups using the corrected excludes list. Obviously, this disk should be far larger in size than what you have used on your OSX Server.

- You might be upgrading to a beefier 64-bit Intel configuration for your OpenDirectory master or just upgrading in place on the old hardware. I recommend using this on new hardware. Take that clone disk and boot off of it on the new box, and then clone yet again to the local disk or array. Now you can do an in place upgrade to 10.6 on non-production hardware, test, etc. Your previous master is now your first replica when you go production. If you upgrade in place, you should first test that the boot disk works as your primary first, but now you do have a full production-worthy backup disk.

- Once you past a certain point in time, I'd remove the backupdbs on that external disk (don't erase it) and reuse it for Time Machine again. You now have a way to revert to 10.5 pre-upgrade or revert to any 10.6 point in time. You should check the exclusions file before commencing Time Machine backups to make sure you are getting the expected full server backup.

- Profit