Soon after getting my Mac, I obviously wanted to sort the backups out, and to make them much more sensible than my previous PC-based lashup. I've still not really tested out a restore from Mozy, but I like that it's a secure, remote, service, and that for 2GB it's free. The OS X configuration client is slow and crashes easily (yes, a beta in action not just in name), but the underlying backup appears to happen without problem. It's just doing a backup of my working documents, not the OS or music etc.But what about Time Machine, arguably the biggest addition to Leopard (OS X 10.5)? It was time to look it over, now I'm on a point release or two on from 10.5.0, and people do seem to like it. So, worth trying a full system set-and-forget backup with it. You need a second disk, which can be external, for it, and (in my case) that's at least 37GB. I already had an external 150GB drive, with some backups from the PCs on it. I tried just mounting that, and Time Machine refused to use it, as it didn't have an HFS+ partition. The rest of this post is how I achieved that. Non-geeks look away now.I wanted to keep the existing data, so I went back to the PC and used my tried-and-trusted PartitionMagic tool to shrink the existing partition down and create a new empty 70GB one. (I'm not sure if there's a tool in OS X to do this whilst keeping the old data. I wasn't about to make a mistake there.) Then some googling turned up these old instructions for making a FAT32 and an HFS+ partition. Given I'm not needing the HFS+ partition to be bootable, which is the main debate of that thread, it turned out the only necessary parts were:

  • ls /dev/rdisk? with and without the external drive mounted, to find the drive device name (/dev/rdisk2 in my case)
  • ls /dev/rdisk2* to find the volume name of the second partition
  • sudo diskutil eraseVolume "Journaled HFS+" TMBACKUP /dev/disk2s5 to fill it with a nice new HFS+ partition, and mount it.

The 37GB is what it needs for its backup - which is ignoring my music and movie files. As far as I can tell, it's not achieving any compression, as the OS and data comes to about 37GB at the moment. After an hour or two of the initial backup it showed a figure that made me gulp: Backing up 1,075,096 items. Yee-ouch! These modern OSes sure are complex ...

AuthorJonathan Clark