CentOS Stream 8
Sponsored Link

Ceph Pacific : Add or Remove Monitors
2021/07/08
 
This is how to add or remove Monitor Daemons from exisiting Cluster.
                                         |
        +--------------------+           |           +----------------------+
        |   [dlp.srv.world]  |10.0.0.30  |  10.0.0.31|    [www.srv.world]   |
        |     Ceph Client    +-----------+-----------+        RADOSGW       |
        |                    |           |           |                      |
        +--------------------+           |           +----------------------+
            +----------------------------+----------------------------+
            |                            |                            |
            |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] For example, Add a [node04] node for Monitor Daemon on Admin Node.
# transfer public key

[root@node01 ~]#
ssh-copy-id node04

# if Firewalld is running, allow service

[root@node01 ~]#
ssh node04 "firewall-cmd --add-service=ceph-mon; firewall-cmd --runtime-to-permanent"

# install required packages

[root@node01 ~]#
ssh node04 "dnf -y install centos-release-ceph-pacific epel-release; dnf -y install ceph"
# configure monitor map

[root@node01 ~]#
FSID=$(grep "^fsid" /etc/ceph/ceph.conf | awk {'print $NF'})

[root@node01 ~]#
NODENAME="node04"

[root@node01 ~]#
NODEIP="10.0.0.54"

[root@node01 ~]#
monmaptool --add $NODENAME $NODEIP --fsid $FSID /etc/ceph/monmap

monmaptool: monmap file /etc/ceph/monmap
monmaptool: set fsid to 946f2552-23a1-4066-82f3-1c57a2dfed92
monmaptool: writing epoch 0 to /etc/ceph/monmap (2 monitors)

# configure Monitor Daemin

[root@node01 ~]#
scp /etc/ceph/ceph.conf node04:/etc/ceph/ceph.conf

[root@node01 ~]#
scp /etc/ceph/ceph.mon.keyring node04:/etc/ceph

[root@node01 ~]#
scp /etc/ceph/monmap node04:/etc/ceph

[root@node01 ~]#
ssh node04 "ceph-mon --cluster ceph --mkfs -i node04 --monmap /etc/ceph/monmap --keyring /etc/ceph/ceph.mon.keyring"

[root@node01 ~]#
ssh node04 "chown -R ceph. /etc/ceph /var/lib/ceph/mon"

[root@node01 ~]#
ssh node04 "ceph auth get mon. -o /etc/ceph/ceph.mon.keyring"

[root@node01 ~]#
ssh node04 "systemctl enable --now ceph-mon@node04"

[root@node01 ~]#
ssh node04 "ceph mon enable-msgr2"
[root@node01 ~]#
ceph -s

  cluster:
    id:     946f2552-23a1-4066-82f3-1c57a2dfed92
    health: HEALTH_OK

  services:
    mon: 2 daemons, quorum node01,node04 (age 56m)
    mgr: node01(active, since 76m)
    osd: 4 osds: 4 up (since 65m), 4 in (since 66m)

  data:
    pools:   1 pools, 1 pgs
    objects: 0 objects, 0 B
    usage:   22 MiB used, 320 GiB / 320 GiB avail
    pgs:     1 active+clean
[2] To remove a Monitor Daemon from existing Cluster, run commands like follows.
For example, Remove [node04] node.
[root@node01 ~]#
ceph -s

  cluster:
    id:     946f2552-23a1-4066-82f3-1c57a2dfed92
    health: HEALTH_OK

  services:
    mon: 2 daemons, quorum node01,node04 (age 56m)
    mgr: node01(active, since 76m)
    osd: 4 osds: 4 up (since 65m), 4 in (since 66m)

  data:
    pools:   1 pools, 1 pgs
    objects: 0 objects, 0 B
    usage:   22 MiB used, 320 GiB / 320 GiB avail
    pgs:     1 active+clean

# remove Monitor Daemon

[root@node01 ~]#
ceph mon remove node04

removing mon.node04 at [v2:10.0.0.54:3300/0,v1:10.0.0.54:6789/0], there will be 1 monitors
# disable monitor daemon

[root@node01 ~]#
ssh node04 "systemctl disable --now ceph-mon@node04.service"

[root@node01 ~]#
ceph -s

  cluster:
    id:     946f2552-23a1-4066-82f3-1c57a2dfed92
    health: HEALTH_OK

  services:
    mon: 1 daemons, quorum node01 (age 22s)
    mgr: node01(active, since 86m)
    osd: 4 osds: 4 up (since 75m), 4 in (since 76m)

  data:
    pools:   1 pools, 1 pgs
    objects: 0 objects, 0 B
    usage:   22 MiB used, 320 GiB / 320 GiB avail
    pgs:     1 active+clean
Matched Content