Prepare for a little bit of geek-talk.
I’ve been thinking a lot about backups lately. I have regular backups, but not of all of my data. What’s worse is that the data that isn’t regularly backed up is the data that would be the most difficult to replace.
Currently my only personal computer is my little white MacBook. My little white MacBook has a little 80 Gb hard disk in it–plenty for OS X and applications, not very much for data. As a consequence of this I bought a Western Digital My Book external drive to store my data.
My current external drive is a 500 Gb firewire drive, and it still has a little over 100 Gb of free space. I use Time Machine with this drive, which consumes 100-150 Gb of the space. Time Machine backs up the OS, my applications, some documents, and general day-to-day stuff. The external drive is also the primary (and only) source for my iPhoto and iTunes libraries. Because these data stores exist only on the external drive there is no backup of this. Furthermore, all other data that is only stored on this drive is not backed up; the majority of the remaining data is non-original and could be regenerated.
So I’ve been trying to think of a way to have a backup. My mind went to a mirrored RAID of two drives, preferably done in hardware, that would support a firewire connection for Time Machine. This is relatively costly, however. I thought about doing this myself with daisy-chained firewire drives, but this would end up being difficult to maintain.
I think I have decided to buy another external drive of 1 Tb in size that will be used for Time Machine backups only. I would have both my laptop hard drive and my current external hard drive backup with Time Machine to the new external hard drive. I would exclude the current external drive’s Time Machine backup folder so that I could retain the Time Machine data that I have, without making an additional copy of it. (No need to start backing up a backup.)
I think this will resolve my concerns for backing up my larger data stores (iPhoto library in particular). Any comments on what you do, or how this could be done better?