Apple Event: May 7th at 7 am PT

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Cannot Unmount or Eject Time Machine Volume?

This appears to be a bug. After you select an external drive for use as a Time Machine volume, the drive can no longer be unmounted or ejected. This is even true after you turn the volume back into a normal drive.

Solution: Set Time Machine's backup disk to "None", and then either reboot, or just yank the drive if you're in a hurry (not recommended). When you come back up, the drive should be unmountable.

Yes, I realize that you can always manually "unmount" the drive by yanking the cable, but if you need to get in there with Disk Utility to repair or partition the drive, you'll be unable to, unless you go through the solution discussed above.

12" PowerBook G4 and Core Duo Mac Mini, Mac OS X (10.5), Airport Express, iPod nano (1G), LaCie Mini 500 GB

Posted on Nov 11, 2007 6:20 AM

Reply
22 replies

Jan 17, 2008 9:43 PM in response to Daniel Todd Currie

I turned on Time Machine for the first time on my MacBook (late 2006) last weekend. I leave my external USB-powered backup drive at home when I take my MacBook to work each day, and the drive keeps running even when my MacBook is asleep so I unmount the Time Machine drive and unplug it each evening when I put the MacBook to bed. I've had no problems at all just selecting the drive on the desktop and hitting CMD-E to “eject” it when TM is not actively copying files.

Some things to look out for - some characters aren't allowed in the disk name, and the partitions must use one of two formats (check the TM Help for details - I don't have my MacBook available at the moment - I'm posting from my old iMac).

Jan 24, 2008 9:58 AM in response to Daniel Todd Currie

The main reason why you can't unmount volumes is because an application is using it. To find out which application you can run the command +*lsof /Volumes/VOLUMENAME*+ changing VOLUMENAME for your disk name.

I was unable to unmount/eject my backup disk, using the above command the Address Book was still using it, quitting out of Address book enabled me to eject the disk.

It would be nice if ejecting a disk that's in use it would tell you which applications are using it ofcourse!

Jan 25, 2008 12:23 AM in response to Daniel Todd Currie

Hello,

I've got this problem once ... and found out why (at least one good reason). Here it is. It requires some Unix trivia.

-You can't "unmount a volume" if some process has an opened "handle" on it.

Then, you got to figure out "who" has a lock on it. There are sysadmin tool to do that (fuser), but it's complex. In the case of a Workstation operation - like most of the Macs are, you can try closing all your applications preventively and exit from your account (Ctlr-Cmd-Q), or reboot.

In the case I've identified, it was Time Machine Preferences Pane that was dead, but dead to a point it became a "zombie" process. It means that the process is dead, but the kernel of your Unix machine has not been told it was fully "dead". It's really gone, but the process is still listed as "alive". Hence, the "zombie" name.

I've saved the list of my processes in text file the last time it happened:

501 1063 171 0 0:00.00 ?? 0:00.00 (System Preferenc)

A zombie process is shown in parenthesis. There is not much option - on the system administrator side - to update the kernel process list, but a gentle reboot.

So: nicely close by hand all you applications using the application switcher: Hold Command key down and tap on the Tab key. For each app, tap Q. If the Finder is responsive (it may have been locked up trying to unmount that TM volume) try Restart, or press the PowerKey if your machine has one reachable (or Command-Eject for 1").

---> Now: Why did TM got hosed like that? First, I don't know and have reported it.

In my case, I've setup my Mac to not login onto my account by default.

If I plug my Fw TM drive BEFORE logging in, then TM goes into an endless loop telling "Preparing" ... but under the hood TM is already "zombified".

So: Always plug your TM drive once you're logged in ... until further notice.

If this description doesn't match your case, anyways, my description above is always true: You can't unmount a Volume if some process has a lock on it.

Hoping this helps.
Thierry

Cannot Unmount or Eject Time Machine Volume?

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.