[ceph-users] Howto add DB (aka RockDB) device to existing OSD on HDD

Hi, I have created OSD on HDD w/o putting DB on faster drive. In order to improve performance I have now a single SSD drive with 3.8TB. I modified /etc/ceph/ceph.conf by adding this in [global]: bluestore_block_db_size = 53687091200 This should create RockDB with size 50GB. Then I tried to move DB to a new device (SSD) that is not formatted: root@ld5505:~# ceph-bluestore-tool bluefs-bdev-new-db –-path /var/lib/ceph/osd/ceph-76 --dev-target /dev/sdbk too many positional options have been specified on the command line Checking the content of /var/lib/ceph/osd/ceph-76 it appears that there's no link to block.db: root@ld5505:~# ls -l /var/lib/ceph/osd/ceph-76/ insgesamt 52 -rw-r--r-- 1 ceph ceph 418 Aug 27 11:08 activate.monmap lrwxrwxrwx 1 ceph ceph 93 Aug 27 11:08 block -> /dev/ceph-8cd045dc-9eb2-47ad-9668-116cf425a66a/osd-block-9c51bde1-3c75-4767-8808-f7e7b58b8f97 -rw-r--r-- 1 ceph ceph 2 Aug 27 11:08 bluefs -rw-r--r-- 1 ceph ceph 37 Aug 27 11:08 ceph_fsid -rw-r--r-- 1 ceph ceph 37 Aug 27 11:08 fsid -rw------- 1 ceph ceph 56 Aug 27 11:08 keyring -rw-r--r-- 1 ceph ceph 8 Aug 27 11:08 kv_backend -rw-r--r-- 1 ceph ceph 21 Aug 27 11:08 magic -rw-r--r-- 1 ceph ceph 4 Aug 27 11:08 mkfs_done -rw-r--r-- 1 ceph ceph 41 Aug 27 11:08 osd_key -rw-r--r-- 1 ceph ceph 6 Aug 27 11:08 ready -rw-r--r-- 1 ceph ceph 3 Aug 27 11:08 require_osd_release -rw-r--r-- 1 ceph ceph 10 Aug 27 11:08 type -rw-r--r-- 1 ceph ceph 3 Aug 27 11:08 whoami root@ld5505:~# more /var/lib/ceph/osd/ceph-76/bluefs 1 Questions: How can I add DB device for every single existing OSD to this new SSD drive? How can I increase the DB size later in case it's insufficient? THX