Ceph: "[WRN] LARGE_OMAP_OBJECTS: xx large omap objects" for CephFS Metadata Pool

Issue

The command ceph health details reports "[WRN] LARGE_OMAP_OBJECTS: xx large omap objects" for CephFS Metadata Pool

Example:

sh-4.4$ ceph status
  cluster:
    id:     e83cxxxx-cluster-identifier-obfuscated-yyyyc3b9a414
    health: HEALTH_WARN
            2 large omap objects     <--- Here

  services:
    mon: 3 daemons, quorum a,d,e (age 2d)
    mgr: a(active, since 2d)
    mds: 1/1 daemons up, 1 hot standby
    osd: 3 osds: 3 up (since 2d), 3 in (since 8M)
    rgw: 1 daemon active (1 hosts, 1 zones)

  data:
    volumes: 1/1 healthy
    pools:   11 pools, 177 pgs
    objects: 1.50M objects, 156 GiB
    usage:   560 GiB used, 6.8 TiB / 7.4 TiB avail
    pgs:     177 active+clean

  io:
    client:   12 KiB/s rd, 236 KiB/s wr, 4 op/s rd, 26 op/s wr

sh-4.4$ ceph health detail
HEALTH_WARN 2 large omap objects
[WRN] LARGE_OMAP_OBJECTS: 2 large omap objects
    2 large objects found in pool 'ocs-storagecluster-cephfilesystem-metadata'   <--- Here
    Search the cluster log for 'Large omap object found' for more details.

sh-4.4$ cat ceph_df_detail 
--- RAW STORAGE ---
CLASS     SIZE    AVAIL     USED  RAW USED  %RAW USED
hdd    7.4 TiB  7.0 TiB  424 GiB   424 GiB       5.62
TOTAL  7.4 TiB  7.0 TiB  424 GiB   424 GiB       5.62

--- POOLS ---
POOL                                                   ID  PGS   STORED   (DATA)   (OMAP)  OBJECTS     USED   (DATA)   (OMAP)  %USED  MAX AVAIL  QUOTA OBJECTS  QUOTA BYTES  DIRTY  USED COMPR  UNDER COMPR
ocs-storagecluster-cephfilesystem-metadata              1   32  648 MiB  211 MiB  437 MiB    2.37k  1.0 GiB  633 MiB  437 MiB   0.02    1.9 TiB            N/A          N/A    N/A         0 B          0 B
ocs-storagecluster-cephfilesystem-data0                 2   32   23 GiB   23 GiB      0 B  852.64k  109 GiB  109 GiB      0 B   1.79    1.9 TiB            N/A          N/A    N/A         0 B          0 B
ocs-storagecluster-cephblockpool                        3   32  107 GiB  107 GiB   73 KiB   33.14k  309 GiB  309 GiB   73 KiB   4.91    1.9 TiB            N/A          N/A    N/A         0 B          0 B
ocs-storagecluster-cephobjectstore.rgw.control          4    8      0 B      0 B      0 B        8      0 B      0 B      0 B      0    1.9 TiB            N/A          N/A    N/A         0 B          0 B
ocs-storagecluster-cephobjectstore.rgw.meta             5    8  4.1 KiB  3.7 KiB    434 B       16  2.6 MiB  2.6 MiB    434 B      0    1.9 TiB            N/A          N/A    N/A         0 B          0 B
ocs-storagecluster-cephobjectstore.rgw.log              6    8  4.8 MiB  3.6 KiB  4.8 MiB      213   11 MiB  6.6 MiB  4.8 MiB      0    1.9 TiB            N/A          N/A    N/A         0 B          0 B
ocs-storagecluster-cephobjectstore.rgw.buckets.index    7    8    359 B      0 B    359 B       22    359 B      0 B    359 B      0    1.9 TiB            N/A          N/A    N/A         0 B          0 B
ocs-storagecluster-cephobjectstore.rgw.buckets.non-ec   8    8      0 B      0 B      0 B        0      0 B      0 B      0 B      0    1.9 TiB            N/A          N/A    N/A         0 B          0 B
.rgw.root                                               9    8  4.8 KiB  4.8 KiB      0 B       16  2.8 MiB  2.8 MiB      0 B      0    1.9 TiB            N/A          N/A    N/A         0 B          0 B
ocs-storagecluster-cephobjectstore.rgw.buckets.data    10   32    1 KiB    1 KiB      0 B        1  192 KiB  192 KiB      0 B      0    1.9 TiB            N/A          N/A    N/A         0 B          0 B
device_health_metrics                                  11    1      0 B      0 B      0 B        0      0 B      0 B      0 B      0    1.9 TiB            N/A          N/A    N/A         0 B          0 B

From MON or OSD log file(s):

debug 2022-12-15T09:12:03.941+0000 7f940c105700 0 log_channel(cluster) log [DBG] : 1.c deep-scrub ok
debug 2022-12-15T09:12:07.569+0000 7f940c105700 0 log_channel(cluster) log [WRN] : Large omap object found. Object: 1:89c35100:::10000005b45.01000000:head PG: 1.8ac391 (1.11) Key count: 202070 Size (bytes): 107299180
debug 2022-12-15T09:12:07.614+0000 7f940c105700 0 log_channel(cluster) log [DBG] : 1.11 deep-scrub ok
debug 2022-12-15T09:12:08.601+0000 7f940b103700 0 log_channel(cluster) log [WRN] : Large omap object found. Object: 1:cb0ff638:::1000000631b.01000000:head PG: 1.1c6ff0d3 (1.13) Key count: 206665 Size (bytes): 109739124
debug 2022-12-15T09:12:08.611+0000 7f940b103700 0 log_channel(cluster) log [DBG] : 1.13 deep-scrub ok