There are two types of computer users, those that have lost data and those that will. Yes, I know this is a profound statement, but computers are prone to fail (they are made by humans, who do, of course, make mistakes). I’m very religious about my backups as I have lost data in the past, not much data, but some. For years, I did weekly archives to CDs and then DVDs. These were good as I could go back in time and get old data, but it turns out I never did that. Last year I shredded years of old CDs and DVDs. My current strategy is to protect against hardware failure and software corrupting data. The first part is easy, just backup to an external drive every day. I do this and rotate between 3 drives; one is always offsite in my safe deposit box. I goto my safe deposit every Friday (the tellers know me I’m there so often). This is a great strategy and has served me well. I did have a hard drive failure several years back, but recovered quite easily (not quickly because my most recent backup that was a few hours old was sitting in the safe deposit box that I couldn’t get to for 2 days as I dropped it off on a Saturday). Every day I use SuperDuper! to backup and I’m very pleased with this. I’ve added Time Machine to my mix and that has also saved me. I believe you can never have too many backups. Oh and I forgot, my virtual private server gets an archive created daily and then once a day, it is synced down to my machine and then weekly copied to a drive going to my safe deposit box. So, I’m pretty well covered.
Why did I write all this? I got a panicked email from a user that used Carbon Copy Cloner to backup his drive, erased his computer and then installed Leopard. However, he apparently didn’t verify that this backup (his only one) worked. When he fired up DocumentWallet, all his documents that he had created over the last 8 months were gone and he wanted to know how to get them back. I’m not sure what the final result was, but I told the user where DocumentWallet stores his data and to search his hard drive; hopefully he’ll find his documents. At any given time, I have 4 backups of my data (1 Time Machine and 3 cloned drives with SuperDuper!). Could disaster strike me? Sure, if I delete a file and discover months later that I need it, I won’t have it. This has happened a few times, but it wasn’t critical. With all my source code under Subversion version control, I have another layer of protection that lets me roll back to older versions of my source.
So the moral of my story is make sure you have a backup strategy and always do backups. Either use an automated system or make sure you are extremely consistent about it. (Mine is semi-automated; I have a cron job that launches SuperDuper! everyday at 5 pm and then I shove in one of my drive.)
I don’t backyp my whole main HDD as I have no need. The only real important stuff is my music library which is backed up every few weeks. A few months back I had my external fail while in the process of Dbaning (http://dban.sourceforge.net/) my main HDD. It was alreadyon pass 3 of 4 so recover was out of the question. Fortunately, my iPod was only synced hours ago and had everything but a few videos.
You don’t think you have a need, but rebuilding a machine takes a significant amount of time. As I use my computer all day for work, a day or even a half day of downtime to rebuild a machine is quite costly.