How to unmount a busy device

linux umount
Max picture Max · Oct 24, 2011 · Viewed 685.3k times · Source

I've got some samba drives that are being accessed by multiple users daily. I already have code to recognize shared drives (from a SQL table) and mount them in a special directory where all users can access them.

I want to know, if I remove a drive from my SQL table (effectively taking it offline) how, or even is, there a way to unmount a busy device? So far I've found that any form of umount does not work.

Ignoring the possibility of destroying data - is it possible to unmount a device that is currently being read?

Answer

Amit Verma picture Amit Verma · Nov 14, 2013

YES!! There is a way to detach a busy device immediately (even if it is busy and cannot be unmounted forcefully). You may cleanup all later:

umount -l /PATH/OF/BUSY-DEVICE
umount -f /PATH/OF/BUSY-NFS (NETWORK-FILE-SYSTEM)

NOTE:

  1. These commands can disrupt a running process, cause data loss OR corrupt open files. Programs accessing target DEVICE/NFS files may throw errors OR could not work properly after force unmount.
  2. Do execute these commands when not inside mounted Folder/Drive/Device.

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