Hello Patrick,
File system created around 4 months back. Using ceph version 14.2.3 version.
[root@knode25 /]# ceph fs dump
dumped fsmap epoch 577
e577
enable_multiple, ever_enabled_multiple: 0,0
compat: compat={},rocompat={},incompat={1=base v0.20,2=client writeable ranges,3=default
file layouts on dirs,4=dir inode in separate object,5=mds uses versioned
encoding,6=dirfrag is stored in omap,8=no anchor table,9=file layout v2,10=snaprealm v2}
legacy client fscid: 1
Filesystem 'cephfs01' (1)
fs_name cephfs01
epoch 577
flags 32
created 2019-10-18 23:59:29.610249
modified 2020-02-22 03:13:09.425905
tableserver 0
root 0
session_timeout 60
session_autoclose 300
max_file_size 1099511627776
min_compat_client -1 (unspecified)
last_failure 0
last_failure_osd_epoch 1608
compat compat={},rocompat={},incompat={1=base v0.20,2=client writeable ranges,3=default
file layouts on dirs,4=dir inode in separate object,5=mds uses versioned
encoding,6=dirfrag is stored in omap,8=no anchor table,9=file layout v2,10=snaprealm v2}
max_mds 1
in 0
up {0=2981519}
failed
damaged
stopped
data_pools [2]
metadata_pool 1
inline_data disabled
balancer
standby_count_wanted 1
2981519: [v2:10.131.16.30:6808/3209191719,v1:10.131.16.30:6809/3209191719]
'cephfs01-b' mds.0.572 up:active seq 22141
2998684: [v2:10.131.16.89:6832/54557615,v1:10.131.16.89:6833/54557615]
'cephfs01-a' mds.0.0 up:standby-replay seq 2
[root@knode25 /]# ceph fs status
cephfs01 - 290 clients
========
+------+----------------+------------+---------------+-------+-------+
| Rank | State | MDS | Activity | dns | inos |
+------+----------------+------------+---------------+-------+-------+
| 0 | active | cephfs01-b | Reqs: 333 /s | 2738k | 2735k |
| 0-s | standby-replay | cephfs01-a | Evts: 795 /s | 1368k | 1363k |
+------+----------------+------------+---------------+-------+-------+
+-------------------+----------+-------+-------+
| Pool | type | used | avail |
+-------------------+----------+-------+-------+
| cephfs01-metadata | metadata | 2193M | 78.1T |
| cephfs01-data0 | data | 753G | 78.1T |
+-------------------+----------+-------+-------+