I have a few My Book externals connected to my 2015 late model imac that have worked flawlessly for the last year, but with the El Capitan OS update they now “turn off” every night. I am a photographer and keep customer files on these drives, as well as my Time Machine backup, so I don’t want them turning off like that. Any suggestions on why this is happening and what I can do about it?
If your Mac does not have USB 3.0 ports then it could be a driver issue. Replace the USB 3.0 cable with a Micro USB 2.0 cable to force USB 2.0 mode at all times.
Hello, I have the same problem. To my mac mini server late 2012 (has only USB3) I had connected a NAS which holds four 3TB wd disks and a 3TB external my book studio and a 4 TB book studio. It never disengaged.
At the time I added 2 more studio 4TB externals I also upgraded to el Capitan. So I am not sure if it is the extra disks or el Capitan. Anyway the disks keep disengaging now. With the result that I already lost all data on one 4TB.
What causes the disks to disengage?
All help and Ideas are appreciated. Thanks.