John Beynon

Last week I suffered my first OSX failure on my 2 year old iMac. This machine is on 24×7 with a bit of ’sleep’ here and there. It’s my primary machine at home used for iTunes syncing along with the occasional browser session, nothing too strenuous.

I came home from work on Monday and noticed it was just showing a background wallpaper, no mouse response or such like so I resorted to a hard reboot. On rebooting I was presented with the grey boot background and an image of a flash folder – uh oh! My first Mac boot failure. Now I wouldn’t have been concerned as I use Mozy an online backup tool (a bargain at $4.95 for unlimited backup) but in this case I’d just added a load of videos from my wedding and honeymoon and knew that it was taking a while to backup – one downside of online backup. I also make heavy use of DropBox with symbolic linking so important stuff like bash customisations, ssh keys etc are shared between my machine as well as various project directories so I knew these were all safe.

I booted from the Snow Leopard CD (holding down the C key) to run the disk utility but a verify/repair didn’t work and kept returning ‘Invalid Node Structure’ message. Uh oh! Then I remembered about ‘Target Disk Mode’ using a Firewire cable between two Macs and holding down the ‘T’ key on boot – all this let me connect to was my Vista boot camp partition – ah, so I could browse that but not the OSX partition. I figured out that if it were a hardware problem the Vista partition wouldn’t have booted, but it did.

Still getting nowhere I did a bit of Googling and eventually found software that enabled me to see the contents of the OSX partition so I hurried out and got myself an external 1Tb drive so I could copy the data off resound to the fact I’d be rebuilding this machine – which again wasn’t really a problem since this Mac was originally Tiger, then upgraded to Leopard and subsequently Snow Leopard.

After rebuilding the machine the drive I’d previously purchased was immediately enabled as a Time Machine backup volume, moved the data back from the disk to where it should be on the computer and reinstalled Mozy (after contacting technical support to find out what it would do since it would already have the data backed up and I haven’t restored it from them).

So now reflecting back on this scenario I’ve come to a number of conclusions. Firstly, backup, backup, backup.

• Online backup tools like Mozy, Carbonite are great to get your most important and valuable data (I’m thinking primarily Photos and Videos) out of your house but are severely limited by upload speeds and presumably download speed if you’ve got a lot of data stored to retrieve.
• DropBox is great for smaller content, documents, code repositories (my Rails projects using GIT are in a DropBox folder, no need to remote sync to locations like GitHub)
• Local backup is still essential, getting data out of your house covers you if your house burns down or such like but hardware failure is much more likely – if you’re not already get yourself an external drive to use as a Time Machine vault. I noticed that you can restore a machine from Time Machine backup during the rebuild process – this would have saved me significant time and effort had I already been using Time Machine.
• Lastly, OSX isn’t as rock solid as I thought. There are plenty of ‘Invalid Node Structure‘ results on Google but I couldn’t find any definitive answer/solution to the problem.

Hope that helps someone…

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