Silly question: in looking at the above, this looks like something you did within the EL7 host's console rather than executing over the network?

Basically, trying to determine how much of this would be re-usable in the context of a template-launched VM. Basically - would I be able to take the above actions within a boot-script and boot into a VM that was in a ready-to-be-altered state, then SSH in and do the alteration.

Hi, I not quite sure, but I think this should be possible. I've done all that stuff in a ssh connection without any problems. Just give it a try and let me know :-)

Well, to be honest, the reason I posed the question was that I'd already tried the steps inside of a CentOS 7.3.1611 VirtualBox VM and could never get enough of the systemd-related components to let go of the filesystems so as to allow #7 to happen. I tried stopping/restarting services in a different orders and can still never get `umount` to think that the filesystem's free to unmount (and, attempting to restart dbus pretty much brings the show to a crashing halt)

For anyone else looking for this answer, I had a similar problem and couldn't resize partitions because the filesystem was 'in use'. I tried fuser, dmsystem, lsof and had no results -- couldn't identify the process holding onto the filesystem. In the end I deleted the remaining device, /dev/dm-0 and I could carry on.