Proxmox/OpenVZ Can’t umount (unmount) device or resource busy
Recently when working on an OpenVZ container I was attempting to create a backup. While doing so I kept running into a problem where the server wouldn’t let me unmount the container in order to create the backup. The error you may see in this instance would say “Can’t umount /var/lib/vz/root/OpenVZID device or resource busy”, or “Can’t umount /var/lib/vz/root/100: Device or resource busy TASK ERROR: command ‘vzctl umount 100’ failed: exit code 51″, in this case the container being 100. Here’s how I was able to fix it … (more…)