On Tue, Jan 10, 2017 at 05:25:51PM +0000, Jonathan McDowell wrote:
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
I tried lsof but the only process accessing the drive in question was the journalling process as far as I could see.
The disk is currently being re-mkfs'ed but when it finishes I'll look into umount again.
Thanks.