When using docker-mender-convert on a pretty fresh install of xubuntu 18.04 I keep getting an error (Error: cannot find an unused loop device. Aborting.). The Error happens in stage 9/9.
Unfortunately I haven’t been able to trace the error in any way yet. Does anyone you have any insight into this?
I try to convert a stock raspbian lite image with the following command:
I even tried to increase the number of loop devices of the machine to 64 - and checked that there were 64 loop entries in /dev/. This didn’t change a thing.
Wonder if it is a docker permission thing. The docker-mender-convert will execute with --privileged=true which should give it access to loop devices, but maybe something has changed here.
Can you try to manually verify if you can access loop devices from within docker containers?
I’ll try to find out. Intrestingly enough the mender-convert utility is able to mount some partitions before the error occurs - if I understand things correctly (sorry I’m very new to docker and mender) this also uses loop devices.
can you pls try following
if losetup seems more loop devices. maybe there is some issue with ubuntu 18.04 (or latest docker). I’m using mender-convert on 16.04 without any problems though.
Thanks for your help.
I just figured that the problem was that my Xubuntu installation agressively mounting all available partitions. So it’s a problem in the host system and is resolved by disabling automount during mender-convert.