if ssh session disconnects while chroot environment is set up, mounts are difficult to unmount
The chroot
environment is initially set up with some mounts (/tmp
, /dev
, ...) and then these are unmounted when either the debug shell is exited, or autobuilder is preparing to quit.
In rare cases, zombie processes or other leftover artifacts may cause difficulties in unmounting these special filesystems.
This has occurred once or twice, but isn't common enough to be an urgent problem. In one case, sshd
could not spawn a TTY for new clients after one sshd
process (of several) was killed in an attempt to allow the "busy device or resource" to be unmounted.
The remedy required was ssh root@system reboot
, since getting a shell was impossible.
Note: this issue may actually only apply to the debug shell (need to trap
and clean up?).