Quite how much time should we put into our computer backups? No idea, though it seems I spend too much time on it, particularly this week. I’m happy so far with Time Machine built into OS X from 10.5 on, but the one thing it misses is the ability to boot from the backup it takes. Big deal? Well, if a drive or the whole MacBook goes completely, then you need to do some serious reinstalling before you can get to a base from which you can then start recovering from Time Machine.

Thus encouraged me to try SuperDuper! from Shirt Pocket software. This allows point-in-time backups of whole volumes (for free) or certain parts (if you pay) - and can make them bootable. Like TM, it constrains you to using volumes formatted as HFS+, not any Windows formats, such as FAT32 or NTFS. And you further have to use the GUID Partition Table standard (not APT or MBR) to make it bootable on Intel-based Macs. I have an external drive, so I thought I’d give that a go. I’d not idea how many hours it would take to get it working.

Turns out a bug has crept into OS X v10.5 that makes certain partitioning in Disk Utility fail with the ‘Partition failed Input/Output Error’ message. OS X Tiger (10.4) doesn’t have this problem, which seems to be with weaknesses on external drives for how they’ve implemented the USB standard. I found that trying it on the old MacMini that runs Tiger) didn’t work unfortunately, but trying another tip did. Some reported that using FireWire to the drive sidesteps the issue, so one FE cable purchase later I was able to run it OK on OS X v10.5.2. (This is all according to this Apple support thread which seems to be the most useful on the topic.)

Having sorted that, I’ve now got SuperDuper! to work. It’s simple enough that non-techies can use it succesfully, I reckon. And I can testify that support is super-quick, despite it being a one- or two-man outfit. However, they really don’t help themselves with having some error messages that are much less helpful than they could be, and it doesn’t check for some things that are bound to cause obscure fatal errors after many minutes of operation.

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 …