Adding Manager service

cephadm automatically installs a Manager daemon on the bootstrap node during the bootstrapping process. Use the Ceph orchestrator to deploy additional Manager daemons.

The Ceph orchestrator deploys two Manager daemons by default. To deploy a different number of Manager daemons, specify a different number. If you do not specify the hosts where the Manager daemons should be deployed, the Ceph orchestrator randomly selects the hosts and deploys the Manager daemons to them.

Note: If you want to apply Manager daemons to more than one specific host, be sure to specify all of the host names within the same ceph orch apply command. If you specify ceph orch apply mgr --placement host1 and then specify ceph orch apply mgr --placement host2, the second command removes the Manager daemon on host1 and applies a Manager daemon to host2.

Use the --placement option to deploy to specific hosts.

Prerequisites

A running storage cluster.

Procedure

To specify that you want to apply a certain number of Manager daemons to randomly selected hosts:

Syntax
```
ceph orch apply mgr NUMBER_OF_DAEMONS
```
Example
```
[ceph: root@host01 /]# ceph orch apply mgr 3
```

To add Manager daemons to specific hosts in your storage cluster:

Syntax

ceph orch apply mgr --placement "HOSTNAME1 HOSTNAME2 HOSTNAME3"

Example

[ceph: root@host01 /]# ceph orch apply mgr --placement "host02 host03 host04"