Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.

I am using devstack on Ubuntu 13.10. Once in a while lvs hangs when cleaning the stack. After some investigation, I found that the issue seems to come from a "corrupted" nbd device. Any process that tries to access that device hangs (lvm, vgdisplay, nbd-client, ...).
There is no way to stop those processes (even sudo kill -9 has no effect).

Using strace I found that the hang occurs when opening the nbd device.

stat("/dev/nbd15", {st_mode=S_IFBLK|0660, st_rdev=makedev(43, 240), ...}) = 0
open("/dev/nbd15", O_RDONLY|O_DIRECT|O_NOATIME

Is there a way to clean the nbd device without rebooting the server?

share|improve this question

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.