There doesn't appear to be a way to be notified of unmount attempts at the moment. There is an fschange modification about ten years ago (http://stefan.buettcher.org/cs/fschange/), but that never made it into the kernel.
It looks like it's impossible for mediascanner to automatically back off when an unmount attempt is made. You can kill the mediascanner process and then unmount. (Not of much help to naive user, I admit.) -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to mediascanner2 in Ubuntu. https://bugs.launchpad.net/bugs/1310186 Title: mediascanner prevents unmounting usb device Status in mediascanner2 package in Ubuntu: Triaged Bug description: Trying to unmount a block device I just mounted, I get the following error (sorry for not resetting the locale. It says "Device is busy"): :~$ sudo umount /media/tkluck/tjk-backup umount2: Apparaat of hulpbron is bezig umount: /media/tkluck/tjk-backup: apparaat is bezig (Welke processen het apparaat gebruiken kan mogelijk gevonden worden met behulp van lsof(8) of fuser(1).) umount2: Apparaat of hulpbron is bezig I get the same error in a dialog window when trying to unmount from the file manager. Using lsof shows that the media-scanner daemon is the culprit: tkluck@ultrabook-tjk:~$ lsof /media/tkluck/tjk-backup COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME mediascan 2898 tkluck 16r DIR 252,3 249856 2 /media/tkluck/tjk-backup mediascan 2898 tkluck 17r DIR 252,3 4096 50855937 <REDACTED> mediascan 2898 tkluck 18r DIR 252,3 4096 39080372 <REDACTED> mediascan 2898 tkluck 19r DIR 252,3 12288 39080513 <REDACTED> mediascan 2898 tkluck 20r DIR 252,3 20480 39080525 <REDACTED> mediascan 2898 tkluck 21r DIR 252,3 4096 46792990 <REDACTED> mediascan 2898 tkluck 22r DIR 252,3 4096 46792991 <REDACTED> mediascan 2898 tkluck 23r DIR 252,3 16384 46793749 <REDACTED> mediascan 2898 tkluck 24r DIR 252,3 4096 47317994 <REDACTED> mediascan 2898 tkluck 25r DIR 252,3 4096 47317997 <REDACTED> mediascan 2898 tkluck 26r DIR 252,3 4096 47317999 <REDACTED> Sending it sudo kill -9 2898 solved this for me. This is on Ubuntu GNOME 14.04. I uninstalled the mediascanner2.0 to solve this "once and for all" (which has no other impact since I do not use Unity). My guess is that the scan usually finishes quickly after mounting. But because this particular drive contains a big filetree, it doesn't, resulting in the issue. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mediascanner2/+bug/1310186/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
