About a week after release I ran the 10.6.1 update only to find that it had failed to install. I’m not sure exactly what happened since my typical method of carrying out updates is to click whatever needs clicked then move back to working on whatever other system is available. I do know that I was left with a dialog proclaiming that the update had failed and I should restart. Fine. I restart. Upon restarting the machine – my MacBook Pro circa 2007 – sat at the boot screen (grey screen with the little spinner) for at least 30 minutes. Not good. I restarted again but this time with the verbose boot sequence – Command-V at startup. Turns out the machine could not find a needed kernel extension for SCSI. Not sure why it needs SCSI but apparently the file was lost in the attempted update. It was clear that whatever happened the system was not going to fix itself, and Google wasn’t sure what was happening either as most the posts I could find related to the specific error talked of hardware failures.

The first thing I did was boot from the Snow Leopard media and run the Disk Utility to fix permissions etc. This seems to fix everything about 90% of the time when I do encounter issues on my Mac but this time no joy. I was relieved by the fact I was able to boot from the DVD though as everything Google had showed me indicated that my disk controller had died, but I wasn’t that nervous as I calculate the odds of a hardware failure occurring at precisely the same moment that I execute an update that has failed to be about the same as my spontaneous and instantaneous movement to a completely different location. Next I decided to reinstall Snow Leopard. This got me back up and running with 10.6. Being stubborn I tried the update again. This go around everything seemed to go great but after rebooting I found the system was still reporting 10.6 as the version. So I let it go for a few days until I received another notice from Software Update that 10.6.1 is available. Third time must be the charm because the update proceeded normally as is typical of Apple software. I’m not sure what caused this issue. The one thing I know was different is I lost wireless network access about halfway through the failed update.

I do have just a few notes on the move to Snow Leopard. If you have one machine you depend on don’t do it yet. The reason is simple, despite the fact Apple is passing this off as a simple update release that doesn’t include many new features it should be noted that 64-bit is different from 32-bit. In fact it is very different. Lots of software has the potential to break. I had issues with MacPorts when I completed the initial upgrade, and some of those issues continue do to compatibility issues that have not been fixed in Python. I don’t blame Apple on this one for the issues. These are a result of third party testing and release cycles. Still if you have a critical system performing an upgrade this early in the release cycle is fairly risky. I realize long time Apple users have become accustom to seamless upgrades but this is one of those rare occasions when you’re probably better off letting the dust settle a bit before moving forward. I suspect that the majority of major third party apps will have released updates already and those that have not will within the month but if you depend on something from a smaller publisher you’ll want to check the web sites for info on compatibility before committing to the upgrade.