With the recent launch of Yosemite 10.10, this weekend I sat down to do the upgrade cycle on my macs. Most worked without issue, however my 2010 Mac Pro didn’t work so smoothly. After running the installer, the system just sat there and wouldn’t boot. This system has 2 SSD drives configured as a RAID 0. The installer didn’t seem to like upgrading over the top of this.
Holding down option during boot presented 2 SSD OS X volumes and 2 other volumes. After systematically trying each, eventually I got back to the Mavericks desktop. It appeared no harm was done but Yosemite hadn’t installed.
Thinking I might need to do a wipe of the volume and do a fresh install, I downloaded DiskMaker X (DiskMaker X 4b4). The authors site was down at the time, but you could download from his Facebook page.
I’ve used this utility several times before and it does a good job.
After creating the volume (using just a 32GB SD card and a card reader I had lying around), I trying restarting from this volume (holding option during boot). The installer went through its motions and actually completed the upgrade cycle. I didn’t need to do a fresh install.
It looks like the Yosemite installer just “looses” something on my RAID setup and having the USB boot drive helps it along.
I’m not sure if this is an issue with just my machine, or all RAID volumes. The next step will be to try and upgrade my ageing Mac Mini server. I’ll update this page if it has the same issues.