Listing devices

You can use the ceph-volume lvm list subcommand to list logical volumes and devices associated with a Ceph cluster, as long as they contain enough metadata to allow for that discovery. The output is grouped by the OSD ID associated with the devices. For logical volumes, the devices key is populated with the physical devices associated with the logical volume.

Sometimes, the output of the ceph -s command shows the following error message:
 1 devices have fault light turned on

In such cases, you can list the devices with ceph device ls-lights command that gives the details about the lights on the devices. Based on the information, you can turn off the lights on the devices.

Prerequisites

  • A running IBM Storage Ceph cluster.

  • Root-level access to the Ceph OSD node.

Procedure

  1. List the devices in the Ceph cluster:

    Example 

    [ceph: root@host01 /]# ceph-volume lvm list


====== osd.6 =======

  [block]       /dev/ceph-83909f70-95e9-4273-880e-5851612cbe53/osd-block-7ce687d9-07e7-4f8f-a34e-d1b0efb89920

      block device              /dev/ceph-83909f70-95e9-4273-880e-5851612cbe53/osd-block-7ce687d9-07e7-4f8f-a34e-d1b0efb89920
      block uuid                4d7gzX-Nzxp-UUG0-bNxQ-Jacr-l0mP-IPD8cX
      cephx lockbox secret
      cluster fsid              1ca9f6a8-d036-11ec-8263-fa163ee967ad
      cluster name              ceph
      crush device class        None
      encrypted                 0
      osd fsid                  7ce687d9-07e7-4f8f-a34e-d1b0efb89920
      osd id                    6
      osdspec affinity          all-available-devices
      type                      block
      vdo                       0
      devices                   /dev/vdc
  2. List the devices in the storage cluster with the lights.
    [ceph: root@host01 /]# ceph device ls-lights

{
    "fault": [
        "SEAGATE_ST12000NM002G_ZL2KTGCK0000C149"
    ],
    "ident": []
}
  3. Turn off the lights on the device.
    ceph device light off DEVICE_NAME FAULT/INDENT --force

    Example

    [ceph: root@host01 /]# ceph device light off SEAGATE_ST12000NM002G_ZL2KTGCK0000C149 fault --force