@MattWatson A belated welcome to the Rockstor community.
and:
Unfortunately the df command in linux is yet to become fully btrfs aware. The command you want, to known of a Pool (btrfs volume) usage, is, for the “/” mount point:
btrfs filesystem usage /
this can be shortened to:
btrfs fi us /
That may help to clear this up. Essentially df is not aware of snapshots and the like so can’t properly represent btrfs usage.
To your pool full problem. First config this as the issue via the ‘fi usage’ command and then you need to try and clear some space on the root drive so the system has breathing room. As you suspect it could very well be that systemd is stressing about having no breathing room.
How you clear space depends on what’s going on. You may have used the system drive for a share, i.e. a popular on is the rock-ons-root share. See:
But as btrfs is a copy on write file system and delete counts as a write, you may have to start with small stuff and work you way up to create progressively more breathing space.
The following forum posts may help:
and:
You may well be able to clear some initial space by removing some systemd logs. the --vacumme-time and --vacuum-size options may work for you on this front:
journalctl --vacuum-time=2d
Should clear all but the last 2 days of logs for example.
And if you have used the system drive / pool as a rock-ons-root then there will be lots of docker images and associated snapshots that can also be deleted, assuming you have, as suggested, created dedicated shares (btrfs subvols) for the individual Rockons config and data. If so then deleting the docker associated snapshots will mean you have some additional repair ahead of you in that you will have to force delete the rock-ons database entries before you can re-install them but first things first is to clear some space on the system drive. If the ‘fi usage’ command confirms this to be the cause. But the ‘out of space’ messages are likely just that.
Finally you may want to read this forum thread:
Where there are references to some balance commands that may also help here.
Hope that helps. And if anyone else can jump in here with advise then please do so as I’m currently otherwise engaged unfortunately.