: Partitions "disappeared" from external HD

May 1st, 2007, 09:46 PM
I was setting up a new User account (G4 MDD Dual 1.25/ 2 x 80GB internals/ 1.5GB RAM, OSX.4.9) and changed some Permissions & User settings on an external Firewire drive's 4 partitions - 100GB, 80GB, 80GB, 40GB. Some of the settings didn't take so I trashed the new User account.

Two of the 4 partitions (the two 80GB ones) disappeared from the Desktop. Their icons appear in the lefthand pane of Disk Utility, but as grey generic instead of the orange FW icons. Strangely, unmounting the 2 problem partitions in DU returns the orange FW icons, but greyed out. I've tried repairing the external disc (DU reports no problems), unmounting/shutting off, several restarts with the drive off and on. Nothing worked.

Even more weird, when Retrospect did its automatic daily backup to one of the problem partitions, it ran perfectly. Retrospect "saw" the backup partition even though it's not mounted on the desktop.

I suspect the 2 partitions' Permissions were set to something other than my Admin account when I trashed the new User acccount. I hope I've explained the problem clearly. How do I get the 2 partitions to reappear on the desktop, other than erasing the entire disc and starting over again? Thank you in advance for your help.

May 2nd, 2007, 01:40 PM
Wait for a few replies to come in here. Doing the wrong thing could cause irreversible damage. I suspect you will end up using terminal but will let someone that has encountered this issue reply with specifics.

May 2nd, 2007, 03:08 PM
Thank you for the advice eMacMan. Every bit of data on the external HD is also on one or both of the two internal drives (redundant backups), except for the SuperDuper clone on one of the "disappeared" 80GB partitions and OS9/Classic on the 40GB partition. So I could copy the OS9/Classic data to an internal drive, then erase & repartition the external drive. The only data I would lose is the clone of my main HD which can easily be recloned immediately.

Thanks to redundant backups and lots of HD capacity, I have a simple, non-destructive solution. But for my own edification, and anyone else interested, I'd like to figure out what happened and how to fix it. What if I didn't have the redundant backups??!!

Another interesting clue: I did a search for a file in Spotlight and the 2 "disappeared" partitions appear on the right side of Spotlight's window in the "Where" section. The 2 partitions are working; I just can't get them to appear on my desktop.

May 3rd, 2007, 02:00 PM
I am really guessing as I have not enountered this issue before.

Try this as an admin user.

"Apple-Shift-u" will take you to the utilities folder. Find Terminal and open it.

sudo -s
press "return" You will be asked for your password. Type it in and press return. You will get the unix prompt. Now type:
and press "return". Hopefully the invisible volumes will mount. If they do you can do a "get info" and check the "ignore permissions for this volume" box on the invisible partitions.

You are logged into Terminal as God so it would be a good idea to quit Terminal before you do any damage.

Mount is the unix command to mount volumes and disks, sudo makes you supreme commander and allows you to bypass permissions issues. There is a modifier to force rebellious volumes to mount but I have no way to check it out at the moment. :) Hopefully you won't need it.