MOTUnation.com

Not finding anything out there on this one, any ideas appreciated.

2010 Mac Pro 2.8 quad, 32GB RAM.
Fusion DIY done 6/2015 with fresh 10.10.4 install, since moved to 10.10.5, configured such that there is a recovery drive.
OWC 240GB Mercury Accelsior E2 and Toshiba 1TB 7200 HD.
NVRAM and SMC resets done.

Worked fine for a month, then one morning it appeared (maybe) to have shut down due to power loss, and would not start up. Booted from a different start up disk, ran disk repair successfully (took several passes), up an running again. Adopted nightly shutdown as precaution.

Since then it has mostly refused to boot without repair from alternate boot drive first, and always comes up ok after repair.

It updated to 10.10.5 on 8/21, I believe the first instance of this problem was on 8/18. System is set to download updates in background, and only install system data files and security updates.

Sounds like an SSD issue, as I believe frequently used files, such as those required to start up, reside on the SSD in a fusion setup. Can you reformat as a regular (non-fusion) SSD? Test, then return to OWC if drive is bad.

My initial response would be to reinstall the OS. That is a PITA, obviously.

MIDI Life Crisis wrote:My initial response would be to reinstall the OS. That is a PITA, obviously.

Yea, takes 20 minutes.

Not likely to fix the problem but worth a try. If you have to run several passes in Disk Utitility and it only lasts a short while, the drive is bad. Replace it.

There are many sets of instructions for creating DIY fusion drive. These made the most sense to me:
http://hints.macworld.com/article.php?s ... 0311173257

Now that SSDs have fallen below the $300 point for 1T and $600 for 2T (Samsung 850 EVO) I decided to go that route instead

Problem appears to have started well before the last OS update, and ran fine on the previous, so I'm not putting a lot of faith in that one. This is the second of these SSD's in this computer, the first went bad within a few weeks, before I'd even gotten around to trying a fusion meld, and was replaced by OWC. Need to check the warranty......