Comment 4 for bug 1713239

re #2:

1. Yes, we have one use-case right now for a device used for multiple purposes which requires custom partition tags, in other words, I would expect "blah" to be applied to a partition, not 'blah-part1'.

For an NVMe device:

p1 - cache device (partition) for bcache0
p2 - cache device (partition) for bcache1
p3 - partition device for ceph journal or ceph (wal & db)

So, I would expect:

# all block devices (bcache in our case) tagged as osd-data for ceph osd (works)
juju create-storage-pool osd-devices maas tags=osd-data
# a tag for bcache1 device (works) - used for node-local VM storage
juju create-storage-pool ephemeral maas tags=bcache-ephemeral
# a tag for a journal partition
juju create-storage-pool nvme-journal maas tags=journal,nvme

2. I suppose it would be useful. If a device is partitioned there seems to be no point in adding tags other than ones providing device type information to the partition such as "nvme" and doing that by hand is cumbersome;

3. I guess the approach from comment #3 would solve it.

The most specific request would be:

juju create-storage-pool nvme-journal maas tags=journal,nvme,partition