Hey all, I got an old iMac - Mid 2011 27" i7, 8GB, 256 Apple SSD (model 12,2) - from a customer that just got a new Mid 2017 27" iMac. He wanted me to erase his personal data then said I could do whatever I like with it. Anyway, I booted it to recovery mode, ran Disk Utility and deleted the partition, "Erased" it with a new Mac Journaled partition and then did a fresh install of El Capitan (What was on it when I got it.) And finally, i went to the App store and updated it to Sierra. All is mostly good. It actually runs quite well for its age and seems very snappy. One issue, however. Since the Sierra upgrade: every time it boots I get an error after login about a drive that needs to be initialized. Checking Disk Utility, at the top of the left-side list, is a drive called ST_M13FQBL Media; it is 4.14 GB Uninitialized. For grins, I tried to initialize it... no go. I've run First Aid and it is healthy. Below that weird drive is the expected Apple SSD TS256C Media 251 GB SATA Internal Physical Disk Below that is the Partition I created in the recovery Disk Utility before install that I called Mac_256-SSD I found one reference in the forums from 2014 related to a 320 GB rotational drive where the few responders believed this strange drive showing up indicated a failing Seagate drive. However, I ran First Aide on all drives and partitions and all seems good. Also, the system reinstalled and updated with no issues. Im not getting any freezes or other data corruption. Nor did the customer before this. He replaced this machine because he could, not necessarily because there were any issues. (He did want and ordered a larger SSD, but it wasn't due to an existing hardware issue.) So... I'm stumped. Any ideas? Thanks in advance.