Ceph

I can't remove the writeback cache pool.
Problems :
- Documentation seems outdated : procedure to remote the cache mention to use the `ceph osd tier cache-mode cephfs_data_cache proxy` mode, but this option does not exist. So I used the readproxy instead.
- The cache-flush-evict-all reports many errors (check below).
- The cache pool is not empty (46194 objects remains in the cache pool)

root@pve1:~# ceph osd tier cache-mode cephfs_data_cache readproxy
root@pve1:~# rados -p cephfs_data_cache cache-flush-evict-all
...
failed to flush /1000065c15a.00000000: (2) No such file or directory
        1000082419d.00000001
failed to flush /1000082419d.00000001: (2) No such file or directory
        100008437ce.00000000
failed to flush /100008437ce.00000000: (2) No such file or directory
        1000065b25c.00000000
failed to flush /1000065b25c.00000000: (2) No such file or directory
cache-flush-evict-all finished with errors

root@pve1:~# rados -p cephfs_data_cache ls | wc -l
46194
root@pve1:~# rados -p cephfs_data_cache cache-flush-evict-all 2>&1 | grep 'failed to flush' | grep -v 'No such file or directory' | wc -l
0

At this stage, I don't know if it's safe to set the cache-mode to none and remove it.
How should I fix the issue?

Thanks