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 the 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 umount 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 umount a device that is currently being read?
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: 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.