Adding osds

OSDs are added by triggering add-osd action on each microceph unit. The unit’s underlying machine is understood to house one or more storage devices.

  1. List the available disks on the microceph node:

    juju run microceph/0 list-disks

The output of the above command should specify the OSDs that are already attached to Microceph and any unpartitioned disks that can be used to attach to microceph as OSD.

Running operation 1 with 1 task
  - task 2 on unit-microceph-0
Waiting for task 2...
osds: '[]'
unpartitioned-disks: '[{''model'': '''', ''size'': ''10.00GiB'', ''type'': ''virtio'',
  ''path'': ''/dev/disk/by-id/virtio-71aa0fef-aec9-4129-9''}, {''model'': '''', ''size'':
  ''40.00GiB'', ''type'': ''virtio'', ''path'': ''/dev/disk/by-id/''}]'

  1. Add the unpartitioned disks as OSD to the microceph cluster:

    juju run microceph/0 add-osd device-id=<DISK PATH>

Multiple disks can be added in the add-osd action.

juju run microceph/0 add-osd device-id=<DISK PATH>,<DISK PATH>

The output of add-osd action should look similar to this:

$ juju run microceph/0 add-osd device-id=/dev/disk/by-id/virtio-71aa0fef-aec9-4129-9
Running operation 3 with 1 task
  - task 4 on unit-microceph-0
Waiting for task 4...
status: success

  1. Verify if the disks are added as OSDs to the ceph cluster:

    juju run microceph/0 list-disks

Now the added disks should be visible in osds. Sample output of the above command:

Running operation 5 with 1 task
  - task 6 on unit-microceph-0
Waiting for task 6...
osds: '[{''osd'': ''0'', ''location'': ''microceph2'', ''path'': ''/dev/disk/by-id/virtio-71aa0fef-aec9-4129-9''}]'
unpartitioned-disks: '[{''model'': '''', ''size'': ''40.00GiB'', ''type'': ''virtio'',
  ''path'': ''/dev/disk/by-id/''}]'

  1. Run steps 1,2,3 on all the storage nodes.

  2. Run ceph cluster status to check if OSDs are up:

    juju ssh microceph/leader sudo microceph.ceph status

Sample output is:

cluster:
  id:     edd914f5-fdf8-4b56-bdd7-95d6c5e10d81
  health: HEALTH_OK

services:
  mon: 3 daemons, quorum microceph2,microceph3,microceph4 (age 12m)
  mgr: microceph2(active, since 13m), standbys: microceph3, microceph4
  osd: 3 osds: 3 up (since 34s), 3 in (since 56s)

data:
  pools:   1 pools, 1 pgs
  objects: 2 objects, 577 KiB
  usage:   66 MiB used, 30 GiB / 30 GiB avail
  pgs:     1 active+clean

io:
  client:   938 B/s rd, 43 KiB/s wr, 0 op/s rd, 1 op/s wr

Now the ceph cluster is healthy and ready to use.