Not sure if this is related but I just upgraded to Yosemite from Mavericks a couple weeks ago and my hard drive started hanging with a swod. I’d have maybe 5-10 minutes of usable computer time before everything would screech to a halt. I took it into the Genius bar and they said I had a bad hard drive.
“But this is a late 2012 iMac and I wasn’t having any issues until I upgraded to Yosemite!?”
“Yes sir, well there’s no predicting the life of a HD.”
“Ah, well I haven’t backed up my data so I’ll let you replace the drive as long as I get the drive that’s in there back.”
“Well, we’ll have to charge you for the drive.”
“I know, I’m happy to pay for a new drive.”
“No, we’ll have to charge you for the drive in there if you want it back”
“How Much?”
“$250”
“Are you out of your mind!? Didn’t I already buy the drive when I bought the computer!?”