Comment 1 for bug 1933914

FYI, content of 'osd-devices' is `/dev/disk/by-dname/bcache2 /dev/disk/by-dname/bcache3 /dev/disk/by-dname/bcache4 /dev/disk/by-dname/bcache5 /dev/disk/by-dname/bcache6 /dev/disk/by-dname/bcache7`.

Some logs that maybe interesting from the unit:
2021-06-29 02:19:28 DEBUG juju.worker.uniter.remotestate watcher.go:427 got application change
2021-06-29 02:19:28 DEBUG juju.worker.uniter resolver.go:147 no operations in progress; waiting for changes
2021-06-29 02:20:00 DEBUG juju.worker.uniter.remotestate watcher.go:448 got config change: ok=true, hashes=[26a4c44f83521054789f1277431b1abc01b2cb26aa783a3dbd32246ec9e558ea]
2021-06-29 02:20:00 DEBUG juju.worker.uniter resolver.go:147 no operations in progress; waiting for changes
2021-06-29 02:20:00 DEBUG juju.worker.uniter.operation executor.go:59 running operation run config-changed hook
2021-06-29 02:20:00 DEBUG juju.machinelock machinelock.go:162 acquire machine lock for uniter (run config-changed hook)
2021-06-29 02:20:00 DEBUG juju.machinelock machinelock.go:172 machine lock acquired for uniter (run config-changed hook)
2021-06-29 02:20:00 DEBUG juju.worker.uniter.operation executor.go:90 preparing operation "run config-changed hook"
2021-06-29 02:20:00 DEBUG juju.worker.uniter.operation executor.go:90 executing operation "run config-changed hook"
2021-06-29 02:20:00 DEBUG juju.worker.uniter agent.go:20 [AGENT-STATUS] executing: running config-changed hook
2021-06-29 02:20:00 DEBUG juju.worker.uniter.runner runner.go:595 starting jujuc server {unix @/var/lib/juju/agents/unit-ceph-osd-0/agent.socket <nil>}
2021-06-29 02:20:01 DEBUG worker.uniter.jujuc server.go:204 running hook tool "juju-log"
2021-06-29 02:20:01 DEBUG juju-log Hardening function 'config_changed'
2021-06-29 02:20:01 DEBUG worker.uniter.jujuc server.go:204 running hook tool "config-get"
2021-06-29 02:20:01 DEBUG worker.uniter.jujuc server.go:204 running hook tool "juju-log"
2021-06-29 02:20:01 DEBUG juju-log No hardening applied to 'config_changed'
2021-06-29 02:20:01 DEBUG worker.uniter.jujuc server.go:204 running hook tool "juju-log"
2021-06-29 02:20:01 INFO juju-log old_version: luminous
2021-06-29 02:20:01 DEBUG worker.uniter.jujuc server.go:204 running hook tool "juju-log"
2021-06-29 02:20:01 INFO juju-log new_version: luminous
2021-06-29 02:20:01 DEBUG worker.uniter.jujuc server.go:204 running hook tool "juju-log"
2021-06-29 02:20:01 ERROR juju-log Invalid upgrade path from luminous to luminous. Valid paths are: ['firefly -> hammer', 'hammer -> jewel', 'jewel -> luminous', 'luminous -> mimic', 'mimic -> nautilus', 'nautilus -> octopus']
2021-06-29 02:20:01 DEBUG worker.uniter.jujuc server.go:204 running hook tool "juju-log"
2021-06-29 02:20:01 DEBUG juju-log Updating sysctl_file: /etc/sysctl.d/50-ceph-osd-charm.conf values: {'kernel.pid_max': 2097152, 'vm.max_map_count': 524288, 'kernel.threads-max': 2097152, 'vm.vfs_cache_pressure': 100, 'vm.swappiness'
: 1}

2021-06-29 02:20:02 DEBUG juju-log got journal devs: {'/dev/disk/by-dname/nvme0n1-part3'}
2021-06-29 02:20:02 DEBUG worker.uniter.jujuc server.go:204 running hook tool "juju-log"
2021-06-29 02:20:02 INFO juju-log Skipping osd devices previously processed by this unit: ['/dev/disk/by-dname/bcache7', '/dev/disk/by-dname/bcache2', '/dev/disk/by-dname/bcache3', '/dev/bcache4', '/dev/disk/by-dname/bcache4', '/dev/d
isk/by-dname/bcache5']
2021-06-29 02:20:03 DEBUG config-changed Failed to find physical volume "/dev/bcache2".
2021-06-29 02:20:04 DEBUG worker.uniter.jujuc server.go:204 running hook tool "juju-log"
2021-06-29 02:20:04 DEBUG juju-log Checking for pristine devices: "['/dev/disk/by-dname/bcache6']"

~# ls -lh /dev/disk/by-dname
total 0
lrwxrwxrwx 1 root root 13 Jun 22 21:36 bcache0 -> ../../bcache4
lrwxrwxrwx 1 root root 13 Jun 22 21:36 bcache1 -> ../../bcache6
lrwxrwxrwx 1 root root 13 Jun 22 21:36 bcache2 -> ../../bcache5
lrwxrwxrwx 1 root root 13 Jun 22 21:36 bcache3 -> ../../bcache0
lrwxrwxrwx 1 root root 13 Jun 22 21:36 bcache4 -> ../../bcache3
lrwxrwxrwx 1 root root 13 Jun 22 21:36 bcache5 -> ../../bcache1
lrwxrwxrwx 1 root root 13 Jun 22 21:36 bcache6 -> ../../bcache2
lrwxrwxrwx 1 root root 13 Jun 22 21:36 bcache7 -> ../../bcache7
lrwxrwxrwx 1 root root 15 Jun 22 21:36 nvme0n1-part1 -> ../../nvme0n1p1
lrwxrwxrwx 1 root root 15 Jun 22 21:36 nvme0n1-part2 -> ../../nvme0n1p2
lrwxrwxrwx 1 root root 15 Jun 22 21:36 nvme0n1-part3 -> ../../nvme0n1p3
lrwxrwxrwx 1 root root 10 Jun 22 21:36 sda-part1 -> ../../sda1

~# pvs
  PV VG Fmt Attr PSize PFree
  /dev/mapper/crypt-17cafad7-8464-4d69-978e-a002cfb76b45 ceph-17cafad7-8464-4d69-978e-a002cfb76b45 lvm2 a-- <3.64t 0
  /dev/mapper/crypt-227cdccb-9ce7-4f89-8d67-5c553d6d1558 ceph-227cdccb-9ce7-4f89-8d67-5c553d6d1558 lvm2 a-- <3.64t 0
  /dev/mapper/crypt-2e53bfba-b064-4a5e-85a2-4de2d5deff18 ceph-2e53bfba-b064-4a5e-85a2-4de2d5deff18 lvm2 a-- <3.64t 0
  /dev/mapper/crypt-4e30dbe6-3f8b-439b-95f1-148c0624c464 ceph-4e30dbe6-3f8b-439b-95f1-148c0624c464 lvm2 a-- <3.64t 0
  /dev/mapper/crypt-81dbd78f-6380-4a4a-872b-0d2fe80195ee ceph-81dbd78f-6380-4a4a-872b-0d2fe80195ee lvm2 a-- <3.64t 0
  /dev/mapper/crypt-dc77eb48-09d7-45ff-ab71-54cbc7d46749 ceph-journal-4cf71488-fdee-4ca6-8a36-a9e748b9d788 lvm2 a-- <931.32g <926.32g
  /dev/mapper/crypt-fdb106e4-bd52-4aa9-b63a-ad95094ea329 ceph-fdb106e4-bd52-4aa9-b63a-ad95094ea329 lvm2 a-- <3.64t 0

crypt-2e53bfba-b064-4a5e-85a2-4de2d5deff18 is /dev/sdd, /dev/bcache2 and therefore /dev/disk/by-dname/bcache6