iMac + new SSD = iTunes borked

Replacing the DVD player in my 27″ iMac with an SSD broke iTunes, yielding a -45054 error. I determined it was crying about the iTunes Store authentication, so I signed out, and when attempting to sign back in, received this error:

“there was an error storing your authorization information on this computer”

There’s an article that describes this error in the Apple Support knowledge base. The information in the article helped me figure out that iTunes was broken because the /Users/Shared directory didn’t exist. I manually created it and the problem is solved. Read on for the nitty gritty details.

I have a Late 2009 27″ iMac that resides on my walking desk downstairs. Now that the kids are back in school, I’m getting back into my habit of working half the day while walking on my treadmill. The only fly in this ointment was how painfully slow the iMac was. If you’re guessing that I’ve been spoiled by the snappy performance of my Retina MacBook Pro, then you’re exactly right.

Rather than replacing the iMac with a newer one, I decided to try a SSD first. I picked up another 250GB Samsung 840 EVO ($200) and yesterday I replaced the DVD/SuperDrive with it. I used Carbon Copy Cloner to sync my spinning disk contents from the spinning disk to the SSD. I did not sync the /Users directory because there’s not enough space on the SSD.

After the fastest boot ever on the new SSD, I visited the Users & Groups control panel and updated each users Home Directory to point to their locations on the old spinning disk. Just like that, my iMac was back to normal. I was able to log in, and everything worked normally. Except iTunes, because /Users/Shared didn’t exist. After fixing that, everything is back to normal, except way, way faster.