What's the safest way...force eject an external hard drive?

lyartetc wrote:

When I try to eject my 1TB external hard drive, I get the error message “one or more programs may be using it.” When I tried to eject it from Utilities

You mean Disk Utility.

Can I just shut down my laptop and then turn off the external hard drive after the computer is shut down?

Yes, but if this happens more than once or twice, it's not very practical, is it? You need to find out which app still wants the drive. The way to do this is in Terminal with lsof. Say your 1TB drive's name is ExternalDisk. When you get this message, you should go into Terminal and do

$ lsof | grep ExternalDisk

($ is the prompt; this is case-sensitive, so make sure you capitalise the drive's name correctly).

After a little while, you should get one or more lines listing what files are still open on the 1TB drive. The first word in each line is the app using the open file.

Shutting down should be a good thing to try.

charlie

launch Activity Monitor (Utilities folder) and see what programs are open that may be using it. You could also try ejecting it using Disc Utility.

Shutting down should always work, because all programs are terminated and they stop using the disk. But you often don't have to go that far.

Logging out should also always work, for the same reasons, although the only programs that get terminated are the ones in the user account that is logged out.

If you don't want to log out, quit any apps you are no longer using.

Mac Mail is notorious for hanging onto files that have been attached to emails. If you attached a file from an external disk, Mail might not have let it go. Quitting Mail solves this problem.

The Finder sometimes doesn't let go of files either, like after you do a QuickLook on a file. Normally you can't quit the Finder except using Activity Monitor, so I add the Quit command using a utility like TinkerTool because quitting the Finder definitely helps with some problems.

Another solution is to upgrade to Lion, because I hear that the message is more specific about telling you exactly which program it is that's still using the disk.

you can also drag the external hdd's icon to the trash to eject as well.

shldr2thewheel wrote:

you can also drag the external hdd's icon to the trash to eject as well.

The method of ejecting won't change the outcome if there's an error saying a file is still in use.

This is been going on for 30 years. Why can't the OS do this for us by now? It doesn't seem too hard to program this.

Does this happen on Windows?

Does this happen on Linux?

Shutting down worked for me. I had the exact same problem.

weatherman3 wrote:

This is been going on for 30 years. Why can't the OS do this for us by now? It doesn't seem too hard to program this.

Does this happen on Windows?

Does this happen on Linux?

What would you program? The software would need to read the mind of the user to detect when the human is about to disconnect the drive, and then suspend all read/write operations to protect the file system. But not a moment before the human's mind is read, because you don't want a superfast drive to not move data when you ask it to. The problem of course is that the current state of mind-reading software is pretty primitive.

Windows has the concept of "safe removal." You are supposed to wait until "the device is safe to remove." I don't know about Linux.

You would have a force eject feature like Windows. Then the OS does the work for you, it stops the apps from communicating to the drive and ejects it... Windows has had it for years and I cant believe that OSX does not.

sudo umount -fv disc

from the command line unmounts the disc, but this still doesn't help with the "disc in use" problem for Time Machine

Hi, It may be a bit late but for the benefit of others who have the same problem which appears to happen all too often, here is the solution I found that works.

I went into Utilities/Disc Utilities/Repair Disc for the external drive. It repaired the disc permissions and I was able to eject the external drive in the usual way once that was done. The repair report showed that the reboot permission on the drive had been repaired so that may have been the cause of the problem in the first place.

I was using a 2TB Western Digital Passport Ultra that I had reformatted for Mac on my MacPro running 10.7.5 The drive was reformatted because it was shipped by the seller with the original Windows MS-dos32 format.

Hope this helps.