This is somewhat to help me remember the next time this happens, but maybe someone else out there has had the same problem in the past and this will be here to help them….
I run my iMac in what Apple Care told me was an “unsupported” configuration on the phone, though they said the genius bar could maybe help. Basically I run my entire /user from an external drive, not the internal drive. I do this for various reasons… I like all my data in one place, rather than just having each application like itunes or imovie point to the external drive…
Anyway, in the year that I’ve run this, I’ve had the following problem happen 3 times. Twice were due to power issues — even though I run a UPS, sometimes it doesn’t keep the charge long enough if I’m not close by to shut-down when we lose power. The other time I accidentally knocked out the firewire cable of the external drive where /users is kept. When the power comes back or when I plugged the cable back in, I was signed into my “sean” account, but it was not my real account, and everything was different. 😦 It is quickly obvious as the desktop image is the default OSX image instead of my normal image.
After digging into it, I saw that I was on a /users on the internal drive, not the external drive. What happens is the mount point name of the external drive is changed to “ext_drive_1” instead of “ext_drive,” the OS can’t find my normal user account, so it uses the internal drive. OS X assigns map points when the drive is attached, and remembers them when it is detached, and for some reason, it gets confused about the drive and gives it a new name.
The solution for this is as follows:
- sign in as admin, not sean
- drag the drives imac24data and imactimemachine to trash (imactimemachine is serially connected to imac24data, so they both need to be taken offline)
- from terminal go to /Volumes
- sudo su
- rm -r iMac24Data (this is where the wrong mount point gets cleared)
- wait a few seconds, plug back in the drive
- login to sean and all should be well