Like your Star Letter correspondent Kenneth Watkins ( MF287), I had deferred upgrading and was using OS X Lion on a mid-2011 27-inch iMac, purchased earlier this year. Time Capsule started to misbehave, culminating in it starting all over again in March, with all previous backups no longer being accessible. It then insisted on spending interminable hours indexing, while at the end of March the backups from early March became inaccessible. The loss of the earlier backups was no big deal, as I also save about once a month on a separate external hard disk, but the ongoing indexing was a pain.
I recently upgraded my broadband, so I decided to download Yosemite and all went well – almost. The download took about 20 minutes and then the installation started, but stuck short of completion. I left it that way for 12 hours while I explored the options. The general consensus seemed to be that if the process did not resume, the best thing to do was force a shutdown and, in most cases, you would (probably) be okay and all would be well on restart. But my concern was that in my enthusiasm to upgrade, I had omitted doing a full backup on the external disk, so if there was a catastrophe, and especially if Time Capsule was mucked up, I could be in trouble.
So with great trepidation, I forced the shutdown on the following morning, started again, and waited very, very anxiously. My Mac started, gradually sorted itself out, and opened successfully in Yosemite. I checked around, and everything seemed in order, all my stuff was still there and up to date and, wonder of wonders, the Time Capsule backups from early March had reappeared.
I’ve had no major issues with Yosemite or with most of the upgraded apps. There are some minor issues with Photos, substituting for iPhoto, but I have retrieved an older Pictures Library and reckon going through the process of migrating that library to Photos all over again may resolve the problems.
So I would say to Kenneth Watkins, go ahead and upgrade if your machine can accept the upgrade. I had always been slow to move forward, even back in the old pre-OS X days, but apart from when a very old machine means that you have reached the upgrade limit, I will never again lag behind as I did over the last few years. Michael J. Walsh Alan Stonebridge says… We’ve had many letters warning of upgrade issues but we think the number of them with Yosemite have been very few on the whole. We understand the frustration with upgrading to newer versions of OS X but Apple, on the whole, handles this well. It can be disconcerting when an install seems to have frozen and you have to use a brute-force measure, but we’re glad it worked for you. It’s not recommended practice though; the installer might seem to have failed but it simply may not be finished.
Remember that OS X’s Recovery mode, paired with a full backup of your system made using Time Machine, can be used later if you’re concerned about something that may have been lost during an update. This even enables you to roll back the system to an earlier major version of OS X.