Ceph Tentacle : Cephadm #2 Configure Cluster2026/04/27

Configure Ceph Cluster with [Cephadm] that is a Ceph Cluster Deploy tool.

For example on here, Configure Ceph Cluster with 3 Nodes like follows.
Furthermore, each Storage Node has a free block device to use on Ceph Nodes.
(use [/dev/sdb] on this example)

                                         |
            +----------------------------+----------------------------+
            |                            |                            |
            |10.0.0.51                   |10.0.0.52                   |10.0.0.53 
+-----------+-----------+    +-----------+-----------+    +-----------+-----------+
|   [node01.srv.world]  |    |   [node02.srv.world]  |    |   [node03.srv.world]  |
|     Object Storage    +----+     Object Storage    +----+     Object Storage    |
|     Monitor Daemon    |    |                       |    |                       |
|     Manager Daemon    |    |                       |    |                       |
+-----------------------+    +-----------------------+    +-----------------------+

[1]	Configure basic Cluster settings with [Cephadm], refer to here.
[2]	To add Nodes to Cluster, run like follows. For example, add [node02], [node03].

# transfer SSH public key

root@node01:~#

ssh-copy-id -f -i /etc/ceph/ceph.pub root@node02


Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'root@node02'"
and check to make sure that only the key(s) you wanted were added.

root@node01:~#

ssh-copy-id -f -i /etc/ceph/ceph.pub root@node03


Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'root@node03'"
and check to make sure that only the key(s) you wanted were added.

# add target Nodes to Cluster

root@node01:~#

ceph orch host add node02.srv.world

Inferring fsid 599755ca-41f6-11f1-8000-525400a2faeb
Inferring config /var/lib/ceph/599755ca-41f6-11f1-8000-525400a2faeb/mon.node01/config
Added host 'node02.srv.world' with addr '10.0.0.52'

root@node01:~#

ceph orch host add node03.srv.world

Inferring fsid 599755ca-41f6-11f1-8000-525400a2faeb
Inferring config /var/lib/ceph/599755ca-41f6-11f1-8000-525400a2faeb/mon.node01/config
Added host 'node03.srv.world' with addr '10.0.0.53'

root@node01:~#

ceph orch host ls

Inferring fsid 599755ca-41f6-11f1-8000-525400a2faeb
Inferring config /var/lib/ceph/599755ca-41f6-11f1-8000-525400a2faeb/mon.node01/config
HOST              ADDR       LABELS  STATUS
node01.srv.world  10.0.0.51  _admin
node02.srv.world  10.0.0.52
node03.srv.world  10.0.0.53
3 hosts in cluster

[3]	To configure OSD, run like follows. For example, configure [node01], [node02], [node03].

# list available devices
# possible to set if [AVAIL = True]

root@node01:~#

ceph orch device ls

Inferring fsid 599755ca-41f6-11f1-8000-525400a2faeb
Inferring config /var/lib/ceph/599755ca-41f6-11f1-8000-525400a2faeb/mon.node01/config
HOST              PATH      TYPE  DEVICE ID   SIZE  AVAILABLE  REFRESHED  REJECT REASONS
node01.srv.world  /dev/vdb  hdd               160G  Yes        9m ago
node02.srv.world  /dev/vdb  hdd               160G  Yes        62s ago
node03.srv.world  /dev/vdb  hdd               160G  Yes        8s ago

# configure OSD

root@node01:~#

ceph orch daemon add osd node01.srv.world:/dev/vdb

Inferring fsid 599755ca-41f6-11f1-8000-525400a2faeb
Inferring config /var/lib/ceph/599755ca-41f6-11f1-8000-525400a2faeb/mon.node01/config
Created osd(s) 0 on host 'node01.srv.world'

root@node01:~#

ceph orch daemon add osd node02.srv.world:/dev/vdb

Inferring fsid 599755ca-41f6-11f1-8000-525400a2faeb
Inferring config /var/lib/ceph/599755ca-41f6-11f1-8000-525400a2faeb/mon.node01/config
Created osd(s) 1 on host 'node02.srv.world'

root@node01:~#

ceph orch daemon add osd node03.srv.world:/dev/vdb

Inferring fsid 599755ca-41f6-11f1-8000-525400a2faeb
Inferring config /var/lib/ceph/599755ca-41f6-11f1-8000-525400a2faeb/mon.node01/config
Created osd(s) 2 on host 'node03.srv.world'

root@node01:~#

ceph -s

Inferring fsid 599755ca-41f6-11f1-8000-525400a2faeb
Inferring config /var/lib/ceph/599755ca-41f6-11f1-8000-525400a2faeb/mon.node01/config
  cluster:
    id:     599755ca-41f6-11f1-8000-525400a2faeb
    health: HEALTH_WARN
            9 failed cephadm daemon(s)
            mon node01 is low on available space

  services:
    mon: 1 daemons, quorum node01 (age 14m) [leader: node01]
    mgr: node01.vgndmp(active, since 13m)
    osd: 3 osds: 1 up (since 4m), 3 in (since 3m)

  data:
    pools:   0 pools, 0 pgs
    objects: 0 objects, 0 B
    usage:   27 MiB used, 160 GiB / 160 GiB avail
    pgs:

Matched Content