I have an external USB harddisk that I have scripted to safely shut down after a backup, so the backup operator can unplug it, and knows not to if the lights are still on for some reason.
It's always worked fine using the DevEject command-line utility. This week it failed for some reason:
DevEject 1.0 2003 c't/Matthias Withopf
Ejecting 'USB Mass Storage Device' [USB\VID_0411&PID_002A\00000704C8D2]...FAILED (23,5)
Error ejecting device USB Mass Storage Device, vetoed (15,5)!
Worse yet, using the SRH tray icon, I click Stop, click OK, it pauses about 5 seconds with OK and Cancel greyed out, closes the sub-window, and then the main window with the Stop button still shows the device, and Stop is still available. I can keep doing that and it never gets rid of the device. I can still access it in Explorer.
LockHunter reports that nothing is locking the drive.
I've made no changes to the backup configuration or anything to do with the drive this week. Why the sudden flake-out? Short of a restart, which I can't do today before the backup operator goes home, how do I fix it?
Things like this sometimes "just happen"; it happened to me, too, and not only with external devices: files locked for no apparent reason, and even Process Explorer couldn't detect what was locking them.
You could just unplug the drive, but this might cause filesystem/data corruption.
My best bet would be to just restart the system.
The drive's USB hardware might actually be starting to fail.