Comment 3 for bug 1718699

I can confirm this issue. Encountered it myself on one node. After booting to the rescue mode I found out that a bcache signature was still present.

ubuntu@jkt01z03nova003:~$ sudo blkid
/dev/sdd: UUID="bf3a9242-cb68-40b9-b2a3-d4c72894fb79" TYPE="bcache"

Interestingly, the commissioning process always succeeds while the deployment process consistently fails. During deployment there are multiple devices: /dev/sdd and /dev/sdf present.

Error messsage (verbose curtin log):
http://paste.ubuntu.com/25730909/

      finish: cmd-install/stage-partitioning/builtin/cmd-block-meta: FAIL: removing previous storage devices
        finish: cmd-install/stage-partitioning/builtin/cmd-block-meta: FAIL: curtin command block-meta
        Traceback (most recent call last):
          File "/curtin/curtin/commands/main.py", line 215, in main
            ret = args.func(args)
          File "/curtin/curtin/commands/block_meta.py", line 67, in block_meta
            meta_custom(args)
          File "/curtin/curtin/commands/block_meta.py", line 1186, in meta_custom
            clear_holders.clear_holders(disk_paths)
...
            return next(self.gen)
          File "/curtin/curtin/block/__init__.py", line 807, in exclusive_open
            fd = os.open(path, os.O_RDWR | os.O_EXCL)
        OSError: [Errno 16] Device or resource busy: '/dev/sdd'
        [Errno 16] Device or resource busy: '/dev/sdd'

curtin config + lsscsi in the rescue mode:
http://paste.ubuntu.com/25730923/

ubuntu@jkt01z03nova003:~$ sudo blkid
/dev/sdd: UUID="bf3a9242-cb68-40b9-b2a3-d4c72894fb79" TYPE="bcache"

After a certain point you may start to blame hardware which isn't correct.

`wipefs -a /dev/sdd` successfully removes the bcache signature and solves the issue.