unusable if current BE is not mounted on `/`

[Subito]

A great feature would be to have sync-be work even when the current BE is mounted somewhere else then /. This is the case for example if the BE gets mounted from a LiveCD for recovery purposes etc or just after a fresh install.

Maybe it would be enough to have an option that sets ROOTFS to something else:

sync-be/sync-be

Lines 90 to 95 in 8d6e6e0

	# use the dataset that is being booted from
	ROOTFS=`mount -p | awk '$2 == "/" && $3 == "zfs" { print $1 }'`
	if [ -z "$ROOTFS" ]; then
	echo "error: zfs is not on root"
	exit 1
	fi

If this is something you would consider useful, I'd be glad to prepare a PR.

Cheers,
Filias

[xbeaudouin]

Hi!
Well if you have already something on you side, we will be pleased to add this usefull option.
Kind regards

[Subito]

I think my main question is: Why is this check there in the first place? Is there a reason why it has to check if the dataset is mounted on /? My first instinct was, that this check might be not needed at all and we could just take ROOTFS from e.g $3 if there is no dataset mounted on /.

I'm trying to understand how I can solve this in the best way without affecting any safeguards that might be in place for a very googd reason.

Cheers

[dch]

The check exists so that the rest of the script can be reasonably sure it's running
inside a zfs setup, in a standard FreeBSD boot environment layout, that's all. If not,
it can't e.g. expect that things like /usr/local/etc/ and /var/* are necessarily where
the sync-be config file expects them to be later on in the copying phase.

In other words, if / is not ZFS-based then we should stop early before making a mess.