Configure a Client Host [client] to use Ceph Storage like follows.

        +--------------------+           |
        |[client.srv.local]  |10.0.0.30  |
        |     Ceph Client    +-----------+
        |                    |           |
        +--------------------+           |
            +----------------------------+----------------------------+
            |                            |                            |
            |10.0.0.51                   |10.0.0.52                   |10.0.0.53 
+-----------+-----------+    +-----------+-----------+    +-----------+-----------+
|   [node01.srv.local]  |    |   [node02.srv.local]  |    |   [node03.srv.local]  |
|     Object Storage    +----+     Object Storage    +----+     Object Storage    |
|     Monitor Daemon    |    |                       |    |                       |
|     Manager Daemon    |    |                       |    |                       |
+-----------------------+    +-----------------------+    +-----------------------+

For example, mount as Filesystem on a Client Host.

[1] Transfer SSH public key to Client Host and Configure it from Admin Node.

# transfer public key
root@node01:~# ssh-copy-id client
# install required packages
root@node01:~# ssh client "apt -y install ceph-fuse"
# transfer required files to Client Host
root@node01:~# scp /etc/ceph/ceph.conf client:/etc/ceph/
ceph.conf                                     100%  195    98.1KB/s   00:00
root@node01:~# scp /etc/ceph/ceph.client.admin.keyring client:/etc/ceph/
ceph.client.admin.keyring                     100%  151    71.5KB/s   00:00
root@node01:~# ssh client "chown ceph. /etc/ceph/ceph.*"

[2] Configure MDS (MetaData Server) on a Node.

Configure it on [node01] Node on this example.

# create directory
# directory name ⇒ (Cluster Name)-(Node Name)
root@node01:~# mkdir -p /var/lib/ceph/mds/ceph-node01
root@node01:~# ceph-authtool --create-keyring /var/lib/ceph/mds/ceph-node01/keyring --gen-key -n mds.node01
creating /var/lib/ceph/mds/ceph-node01/keyring
root@node01:~# chown -R ceph. /var/lib/ceph/mds/ceph-node01
root@node01:~# ceph auth add mds.node01 osd "allow rwx" mds "allow" mon "allow profile mds" -i /var/lib/ceph/mds/ceph-node01/keyring
added key for mds.node01
root@node01:~# systemctl enable --now ceph-mds@node01

[3] Create 2 RADOS pools for Data and MeataData on MDS Node.

Refer to the official documents to specify the end number (64 on the example below)
⇒ http://docs.ceph.com/docs/master/rados/operations/placement-groups/

root@node01:~# ceph osd pool create cephfs_data 64
pool 'cephfs_data' created
root@node01:~# ceph osd pool create cephfs_metadata 64
pool 'cephfs_metadata' created
root@node01:~# ceph fs new cephfs cephfs_metadata cephfs_data
new fs with metadata pool 4 and data pool 3
root@node01:~# ceph fs ls
ame: cephfs, metadata pool: cephfs_metadata, data pools: [cephfs_data ]
root@node01:~# ceph mds stat
cephfs:1 {0=node01=up:active}
root@node01:~# ceph fs status cephfs
cephfs - 0 clients
======
RANK  STATE    MDS       ACTIVITY     DNS    INOS
 0    active  node01  Reqs:    0 /s    10     13
      POOL         TYPE     USED  AVAIL
cephfs_metadata  metadata  1536k  74.9G
  cephfs_data      data       0   74.9G
MDS version: ceph version 15.2.3 (d289bbdec69ed7c1f516e0a093594580a76b78d0) octopus (stable)

[4] Mount CephFS on a Client Host.

# Base64 encode client key
root@client:~# ceph-authtool -p /etc/ceph/ceph.client.admin.keyring > admin.key
root@client:~# chmod 600 admin.key
root@client:~# mount -t ceph node01.srv.local:6789:/ /mnt -o name=admin,secretfile=admin.key
root@client:~# df -hT
Filesystem                        Type      Size  Used Avail Use% Mounted on
udev                              devtmpfs  1.9G     0  1.9G   0% /dev
tmpfs                             tmpfs     394M  1.1M  393M   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv ext4       25G  3.1G   21G  14% /
tmpfs                             tmpfs     2.0G     0  2.0G   0% /dev/shm
tmpfs                             tmpfs     5.0M     0  5.0M   0% /run/lock
tmpfs                             tmpfs     2.0G     0  2.0G   0% /sys/fs/cgroup
/dev/loop0                        squashfs   55M   55M     0 100% /snap/core18/1880
/dev/vda2                         ext4      976M  197M  713M  22% /boot
/dev/loop1                        squashfs   56M   56M     0 100% /snap/core18/1885
/dev/loop2                        squashfs   72M   72M     0 100% /snap/lxd/16100
/dev/loop3                        squashfs   71M   71M     0 100% /snap/lxd/16926
/dev/loop4                        squashfs   30M   30M     0 100% /snap/snapd/8542
/dev/loop5                        squashfs   30M   30M     0 100% /snap/snapd/8790
tmpfs                             tmpfs     394M     0  394M   0% /run/user/0
10.0.0.51:6789:/                  ceph       75G     0   75G   0% /mnt