Adding OSDs

Use this information to deploy OSDs on a specific device or host.

Before you begin

Before beginning make sure that you have a running IBM Storage Ceph cluster.

About this task

cephadm does not provision an OSD on a device that is not available. A storage device is considered available if it meets all of the following conditions:

The device must have no partitions.
The device must not be mounted.
The device must not contain a file system.
The device must not contain a Ceph BlueStore OSD.
The device must be larger than 5 GB.

Important: By default, the osd_memory_target_autotune parameter is set to true in IBM Storage Ceph.

For information about tuning OSD memory automatically, see Automatically tuning OSD memory.
For more information about drive specifications for OSDs, see Advanced service specifications and filters for deploying OSDs.
For more information about zapping devices to clear data on devices, see Zapping devices for Ceph OSD deployment.

Procedure

List the available devices to deploy OSDs.

ceph orch device ls [--hostname=HOSTNAME1 HOSTNAME2] [--wide] [--refresh]

For example,

[ceph: root@host01 /]# ceph orch device ls --wide --refresh

You can either deploy the OSDs on specific hosts or on all the available devices.
- Create an OSD from a specific device on a specific host, by using the following command:
```
ceph orch daemon add osd HOSTNAME:DEVICE_PATH
```
  For example,
```
[ceph: root@host01 /]# ceph orch daemon add osd host02:/dev/sdb
```
- Deploy OSDs on any available and unused devices, by using use the --all-available-devices parameter.
  Note: This command creates colocated WAL and DB daemons. To create non-colocated daemons, do not use this command.
```
ceph orch apply osd --all-available-devices
```
  For example,
```
[ceph: root@host01 /]# ceph orch apply osd --all-available-devices
```

What to do next

Verify that the OSDs are added by checking that the Ceph status is in a Healthy state with OSD counts.

For example,

[root@host01 ~]# cephadm shell ceph -s
  cluster:
    id:     8f43ad64-dd03-11ed-8ec8-525400c632ec
    health: HEALTH_OK

  services:
    mon: 3 daemons, quorum host01,host02,host03 (age 94m)
    mgr: host01.lbnhug(active, since 59m), standbys: host02.rofgay, host03.ohipra
    mds: 1/1 daemons up, 1 standby
    osd: 18 osds: 18 up (since 10m), 18 in (since 10m)
    rgw: 4 daemons active (2 hosts, 1 zones)

  data:
    volumes: 1/1 healthy
    pools:   8 pools, 225 pgs
    objects: 230 objects, 9.9 KiB
    usage:   271 MiB used, 269 GiB / 270 GiB
    avail pgs: 225 active+clean
 
  io:
    client: 85 B/s rd, 0 op/s rd, 0 op/s wr