On Tue, Jan 10, 2017 at 02:28:33PM +0000, Chris Green wrote:

Is there any way to unmount an ext4 filesystem without shutting down?

I can do it easily by going to single-user mode or removing the filesystem from /etc/fstab and rebooting but both of these require the system to be shut down.

However it seems to be impossible otherwise because the journalling process makes the filesystem busy. Is this right?

No. The kernel knows to stop the journal when unmounting. There's probably some process with an open file on the filesystem. Try using lsof to see what that might be; e.g. "lsof /mnt" if it's mounted on /mnt J. -- xmpp:noodles@earth.li Life's dangerous enough without mines in the garden.

On 10/01/17 14:28, Chris Green wrote:

Is there any way to unmount an ext4 filesystem without shutting down?

I can do it easily by going to single-user mode or removing the filesystem from /etc/fstab and rebooting but both of these require the system to be shut down.

However it seems to be impossible otherwise because the journalling process makes the filesystem busy. Is this right?

It should be as simple as sudo umount /mnt/mountpoint for the appropriate mountpoint, or sudo umount /dev/sdb1 for the appropriate device & partition number A list of mounted drives can be seen by just typing mount As Jonathon said, something could be using it which could be locking the drive Good luck Steve