I had another Mac Mini grey-screen overnight while copying to the final 2 T of data to the Drobo. When it grey-screens, the Mac Mini heats up and stays running hot. I shut it down this time, and left it off. I'll deal with it when it's cool, and later tonight I'll repair the disks.
Richard reports that his Mac Mini occasionally grey screens too. Richard said that it started with the introduction of Mavericks. But mine was doing it in Yosemite too. I don't think I had my Mac Minis on any of the cat versions of OS X. iOS 8.3 was released yesterday, and Richard reports that his Mac Mini grey-screened in the middle of the update. That is not a good time for the Mac Mini to do that.
I don't do iPhone/iPad updates via iTunes on a Mac. I do them wirelessly. I've been doing it that way since they introduced it. If I get a chance to avoid using iTunes, I will do it. I loathe iTunes. I use it to backup my iDevices, and I use it to move music to them. If I could use something else to move music to them, I would.
I also use iTunes to manage my media library for my Apple TV. But I am about to experiment with Plex and Roku and see if I get a better experience. iTunes is really awful and I hate having to use it for anything.
But enough of my hate for iTunes, what about my hate for the Mac Minis grey-screening? I'm rapidly starting to dislike that a lot.
My Mac Mini Server grey-screened at work over the weekend, and stayed running on hot. For the rest of the weekend. Now when I attempt to turn it on, it waits a few minutes, then emits a low two-tone BEEP-BEEEEP. Then repeats. That Mac Mini is now dead. I've had such good experience with the older fatter white Mac Minis, and such shitty experience with the newer all-metal Mac Minis, that I am considering reducing my Apple exposure a lot.