Tag Archives: mount

umount not possible – device is busy!!!

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Hello everybody,
Welcome to a new issue at UbuntuVideoCast. Did you ever ran into the situation that you have an external storage device attached and now you like to umount it and disconnect it from your system and when you execute for example the command umount /mnt/storage that the system tells you it is not possible because the device is busy? Well here is the solution to figure out who or what is keeping the device busy.
# umount /mnt/storage/
umount: /mnt/storage: device is busy
umount: /mnt/storage: device is busy


What now? The answer is simple use fuser. fuser is a command used to show which processes are using a specified file, file system, or socket.
Here are the options:
-k kills all process accessing a file. For example fuser -k /home/export/ganesh kills all processes accessing this directory without confirmation. Use -i for confirmation
-i interactive mode. Prompt before killing process
-v verbose.
-u append username
-a display all files
-m name specifies a file on a mounted file system or a block device that is mounted. All processes accessing files on that file system are listed. If a directory file is specified, it is automatically changed to name/. to use any file system that might be mounted on that directory.


In order to solve the issue in our example we have to execute the following command:
# fuser -m /mnt/storage
mnt/storage: 15738
# ps auxw| grep
15738user 15738 0.4 2.7 219212 56792 Sep10 11:16 beremote
You should receive something like displayed above. Either close the program, shutdown the service or just kill the process.
I hope that this was helpful to you. Please send me or post any comments, regarding this article or my website. I am happy to receive criticism. I am always looking for a way to improve this website.