I had an issue today with ‘df’ and ‘umount’ hanging because of a problem with my Windows (SMB/Samba/CIFS) share. To force unmount I used:
umount -a -t cifs -l
The above command forces all CIFS mounts to unmount immediately.
I’ve been getting this error from time to time on my Ubuntu server:
INFO: task dpkg:27497 blocked for more than 120 seconds.
I did some research and it turns out this is related to a bug in the dpkg system, and apparently it’s been fixed already (but not rolled out as part of Ubuntu yet).
Look forward to the fixed being rolled out, because the implication of the bug at the moment is that my system can hang for long periods of time while I’m installing software with apt-get.