ok,, I poked the database to get this back to available state.

Can you try and attach it now?

Unfortunately, it still doesn't work. Well, it is not attached to None anymore, but I still get

TASK [copr/frontend-cloud : mount up disk of copr fe] ****************************************************************************************************************************************************************************************
Monday 08 July 2019  19:06:39 +0000 (0:00:00.271)       0:37:13.372 *********** 
fatal: [copr-fe-dev.cloud.fedoraproject.org]: FAILED! => {"changed": false, "msg": "Error mounting /srv/copr-fe: mount: /srv/copr-fe: can't find LABEL=copr-fe.\n"}

from the playbook

Are you able to login to the system at all? It might need some work from the console and fdisk to see if the drive has partitions or labels still

@smooge, yep, I am able to log in via SSH. What should I do?

I've done some magic based on suggestions from @msuchy and got it working by the following procedure. I have ...

1. Detached copr-fe-dev-db volume from copr-fe-dev instance
2. Terminated copr-fe-dev instance because it was unable to boot
3. Executed playbook for provisioning copr-fe-dev instance
4. Created snapshot copr-fe-dev-db-snapshot from copr-fe-dev-db
5. Created copr-fe-dev-db-2 volume from copr-fe-dev-db-snapshot snapshot
6. Attached copr-fe-dev-db-2 volume to copr-fe-dev instance
   - As /dev/vdb instead of desired /dev/vdc, IDK how to change it
7. Executed playbook for provisioning copr-fe-dev instance again

Now I have the volume available and mounted, the original data is there and the database is working.

Do I need to follow-up this with some other steps or I should just update the volume descriptions and leave it be?

Given how hopelessly fragile it is, I would say update the descriptions and call it a day. :)

I agree with kevin. Thanks to msuchy on that.

Drives are named by the order they are seen. For the old system to have a /dev/vdc there needed to be a /dev/vdb at one point so it probably had it for a similar mount/move in the past when it was rebuilt.