On Fri, 2021-03-12 at 19:36 +0800, Ed Greshko wrote:
On 12/03/2021 19:18, Patrick O'Callaghan wrote:
On Fri, 2021-03-12 at 17:01 +0800, Ed Greshko wrote:
On 11/03/2021 21:14, Patrick O'Callaghan wrote:
Someone on the SystemD list suggested using an @reboot line in crontab for this, as a special case.
While I didn't think of that option, I somehow got the impression that you needed/wanted to run a script of some sort each time the share was mounted and unmounted.
I do. The @reboot suggestion is only a partial solution. Given that the drive is automatically powered up on reboot (there seems to be no way to prevent this as it's triggered by the system scanning the USB bus) I need to be able to power it down, but currently there's no systemd mount event to cause this to happen. No doubt there's a more elegant way around this, but baby steps ...
Well, if it can't be done with systemd then a possible inelegant solution is to have a "watcher" background process (or cron job that run periodically) that checks to see if the share has gone from a mounted to unmounted state and then run the appropriate script?
Of course. In the pre-systemd days that would have been the obvious choice. I just thought systemd was supposed to make things more organised, but I'm starting to wonder. I don't want to come across as a systemd sceptic, but IMHO its highly modular structure is reflected in the scattered nature of the documentation, which is a major impediment to really understanding it.
Does something need running when the share goes from unmounted to mounted?
Just a timer. Once it's powered up and mounted, it should stay that way until an idle timeout is triggered.
I suppose this kind of thing is one reason I'm happy I opted for a NAS. It runs a RAID configuration and can be configured to power down disks when idle. :-) :-)
The disks I'm using were actually cannibalised from a NAS that died (after about 10 years use). I stuck them in a dock and aside from this issue they work well. The dock itself does power down after 30 minutes disconnection, but of course while it's mounted that won't happen. I need a script to unmount and then force the disconnection. The script itself works, I just want it to happen automatically.
poc