Describe the issue:

Continuing conversation around https://bugzilla.redhat.com/show_bug.cgi?id=2237412 it was decided to inform user that cephfs metrics are not available. 

Describe the task you were trying to accomplish:
We have a list of metrics that are not exposed to External mode users:

ceph_bluestore_state_aio_wait_lat_sum',
'ceph_paxos_store_state_latency_sum',
'ceph_osd_op_out_bytes',
'ceph_bluestore_txc_submit_lat_sum',
'ceph_paxos_commit',
'ceph_paxos_new_pn_latency_count',
'ceph_osd_op_r_process_latency_count',
'ceph_bluestore_txc_submit_lat_count',
'ceph_bluestore_kv_final_lat_sum',
'ceph_paxos_collect_keys_sum',
'ceph_paxos_accept_timeout',
'ceph_paxos_begin_latency_count',
'ceph_bluefs_wal_total_bytes',
'ceph_paxos_refresh',
'ceph_bluestore_read_lat_count',
'ceph_mon_num_sessions',
'ceph_bluefs_bytes_written_wal',
'ceph_mon_num_elections',
'ceph_rocksdb_compact',
'ceph_bluestore_kv_sync_lat_sum',
'ceph_osd_op_process_latency_count',
'ceph_osd_op_w_prepare_latency_count',
'ceph_paxos_begin_latency_sum',
'ceph_osd_op_r',
'ceph_osd_op_rw_prepare_latency_sum',
'ceph_paxos_new_pn',
'ceph_rocksdb_get_latency_count',
'ceph_paxos_commit_latency_count',
'ceph_bluestore_txc_throttle_lat_count',
'ceph_paxos_lease_ack_timeout',
'ceph_bluestore_txc_commit_lat_sum',
'ceph_paxos_collect_bytes_sum',
'ceph_osd_op_rw_latency_count',
'ceph_paxos_collect_uncommitted',
'ceph_osd_op_rw_latency_sum',
'ceph_paxos_share_state',
'ceph_osd_op_r_prepare_latency_sum',
'ceph_bluestore_kv_flush_lat_sum',
'ceph_osd_op_rw_process_latency_sum',
'ceph_rocksdb_rocksdb_write_memtable_time_count',
'ceph_paxos_collect_latency_count',
'ceph_osd_op_rw_prepare_latency_count',
'ceph_paxos_collect_latency_sum',
'ceph_rocksdb_rocksdb_write_delay_time_count',
'ceph_paxos_begin_bytes_sum',
'ceph_osd_numpg',
'ceph_osd_stat_bytes',
'ceph_rocksdb_submit_sync_latency_sum',
'ceph_rocksdb_compact_queue_merge',
'ceph_paxos_collect_bytes_count',
'ceph_osd_op',
'ceph_paxos_commit_keys_sum',
'ceph_osd_op_rw_in_bytes',
'ceph_osd_op_rw_out_bytes',
'ceph_bluefs_bytes_written_sst',
'ceph_osd_op_rw_process_latency_count',
'ceph_rocksdb_compact_queue_len',
'ceph_bluestore_txc_throttle_lat_sum',
'ceph_bluefs_slow_used_bytes',
'ceph_osd_op_r_latency_sum',
'ceph_bluestore_kv_flush_lat_count',
'ceph_rocksdb_compact_range',
'ceph_osd_op_latency_sum',
'ceph_mon_session_add',
'ceph_paxos_share_state_keys_count',
'ceph_paxos_collect',
'ceph_osd_op_w_in_bytes',
'ceph_osd_op_r_process_latency_sum',
'ceph_paxos_start_peon',
'ceph_mon_session_trim',
'ceph_rocksdb_get_latency_sum',
'ceph_osd_op_rw',
'ceph_paxos_store_state_keys_count',
'ceph_rocksdb_rocksdb_write_delay_time_sum',
'ceph_osd_recovery_ops',
'ceph_bluefs_logged_bytes',
'ceph_bluefs_db_total_bytes',
'ceph_osd_op_w_latency_count',
'ceph_bluestore_txc_commit_lat_count',
'ceph_bluestore_state_aio_wait_lat_count',
'ceph_paxos_begin_bytes_count',
'ceph_paxos_start_leader',
'ceph_mon_election_call',
'ceph_rocksdb_rocksdb_write_pre_and_post_time_count',
'ceph_mon_session_rm',
'ceph_paxos_store_state',
'ceph_paxos_store_state_bytes_count',
'ceph_osd_op_w_latency_sum',
'ceph_rocksdb_submit_latency_count',
'ceph_paxos_commit_latency_sum',
'ceph_rocksdb_rocksdb_write_memtable_time_sum',
'ceph_paxos_share_state_bytes_sum',
'ceph_osd_op_process_latency_sum',
'ceph_paxos_begin_keys_sum',
'ceph_rocksdb_rocksdb_write_pre_and_post_time_sum',
'ceph_bluefs_wal_used_bytes',
'ceph_rocksdb_rocksdb_write_wal_time_sum',
'ceph_osd_op_wip',
'ceph_paxos_lease_timeout',
'ceph_osd_op_r_out_bytes',
'ceph_paxos_begin_keys_count',
'ceph_bluestore_kv_sync_lat_count',
'ceph_osd_op_prepare_latency_count',
'ceph_bluefs_bytes_written_slow',
'ceph_rocksdb_submit_latency_sum',
'ceph_osd_op_r_latency_count',
'ceph_paxos_share_state_keys_sum',
'ceph_paxos_store_state_bytes_sum',
'ceph_osd_op_latency_count',
'ceph_paxos_commit_bytes_count',
'ceph_paxos_restart',
'ceph_bluefs_slow_total_bytes',
'ceph_paxos_collect_timeout',
'ceph_osd_op_w_process_latency_sum',
'ceph_paxos_collect_keys_count',
'ceph_paxos_share_state_bytes_count',
'ceph_osd_op_w_prepare_latency_sum',
'ceph_bluestore_read_lat_sum',
'ceph_osd_stat_bytes_used',
'ceph_paxos_begin',
'ceph_mon_election_win',
'ceph_osd_op_w_process_latency_count',
'ceph_rocksdb_rocksdb_write_wal_time_count',
'ceph_paxos_store_state_keys_sum',
'ceph_osd_numpg_removing',
'ceph_paxos_commit_keys_count',
'ceph_paxos_new_pn_latency_sum',
'ceph_osd_op_in_bytes',
'ceph_paxos_store_state_latency_count',
'ceph_paxos_refresh_latency_count',
'ceph_osd_op_r_prepare_latency_count',
'ceph_bluefs_num_files',
'ceph_mon_election_lose',
'ceph_osd_op_prepare_latency_sum',
'ceph_bluefs_db_used_bytes',
'ceph_bluestore_kv_final_lat_count',
'ceph_paxos_refresh_latency_sum',
'ceph_osd_recovery_bytes',
'ceph_osd_op_w',
'ceph_paxos_commit_bytes_sum',
'ceph_bluefs_log_bytes',
'ceph_rocksdb_submit_sync_latency_count'

Suggestions for improvement:

Document that these metrics are not available. User may reach an External mode ceph cluster to get the metrics, but they will not be available for ODF user

Document URL:

Chapter/Section Number and Title:

Product Version:

Environment Details:

Any other versions of this document that also needs this update:

All supported versions should be updated with this.

Additional information:
* rbd_stats_pools metrics are available for External mode cluster