We observed in production environment that this
Consider fixing the issue by using detach unmount when unmounting container rootfs. See
MESOS-3349 for details.
The root cause on why "Device or resource busy" is received when doing rootfs unmount is still unknown.
UPDATE: The production environment has a cronjob that scan filesystems to build index (updatedb for mlocate). This can explain the EBUSY we receive when doing `unmount`.
UPDATE: Splunk that's scanning `/var/lib/mesos` could also be a source of triggers.