I have mounted an ISO-file to do a network install of Red Hat. Afterwards, I removed the ISO and forgot about the mount.
Now, I am unable to unmount this mount, because the target no longer exists...
Here's the error I get when I try to unmount:
Even if I put all the files back and remount, I cannot unmount is, this is probably because it uses a different inode now.

How can I get rid of this listing in mount? I do not want to reboot this machine, since it has almost 1 year uptime...

You can edit /etc/fstab (and perhaps reboot).

I manually mounted it, so it was not listed in /etc/fstab...

I had kind of hoped to resolve this without a reboot... Thanks anyway.

Try umount -f to force the unmount of the now dead ISO image or try to umount by the mounted sub-dir name:

umount /mnt/some_iso_image_of_redhat

Sigh.... It no longer matters, the problem is solved...

I had a power outage and it took a little longer than the UPS's could provide for... My entire home-network performed a shutdown... Most of these machines had been on for as long as one year...

Bye bye uptime...

What a waste...

Thanks to all who replied!

It was just Mr. Murphy trying to show you the way he wanted it done...

Now thats got to hurt!!