CEPH - persistent write-back cache

[Erik81]

Hi, i try to configure persistent write-back cache but without effect.

root@pve2:~# ceph --admin-daemon  /var/run/ceph/ceph-osd.1.asok config show | grep rbd_cache
    "rbd_cache": "false",

root@pve2:~# ceph --admin-daemon  /var/run/ceph/ceph-osd.1.asok config show | grep rbd_persistent
    "rbd_persistent_cache_log_periodic_stats": "false",
    "rbd_persistent_cache_mode": "rwl",
    "rbd_persistent_cache_path": "/ramdisk",
    "rbd_persistent_cache_size": "1073741824",

root@pve2:~# mount | grep ramd
/dev/pmem0 on /ramdisk type ext2 (rw,relatime,dax)

root@pve2:~# ls -al /ramdisk/
total 8
drwxrwxrwx  2 ceph ceph 4096 Dec  6 19:42 .
drwxr-xr-x 19 root root 4096 Dec  5 16:21 ..

root@pve2:~#  rbd status  test_pool/vm-117-disk-0
Watchers:
        watcher=192.168.239.2:0/1772746076 client.26547634 cookie=139959898036208

Version 16.2.6-pve2. Does it work for anyone?