Setting the OSD memory target

Use the osd_memory_target option to set the maximum memory threshold for all OSDs in the storage cluster, or for specific OSDs.

An OSD with an osd_memory_target option set to 16 GB might use up to 16 GB of memory.
Note: Configuration options for individual OSDs take precedence over the settings for all OSDs.

Prerequisites

  • A running IBM Storage Ceph cluster.

  • Root-level access to all hosts in the storage cluster.

Procedure

  1. To set osd_memory_target for all OSDs in the storage cluster:

    Syntax 

    ceph config set osd osd_memory_target VALUE

    VALUE is the number of GBytes of memory to be allocated to each OSD in the storage cluster.

  2. To set osd_memory_target for a specific OSD in the storage cluster:

    Syntax 

    ceph config set osd.id osd_memory_target VALUE

    .id is the ID of the OSD and VALUE is the number of GB of memory to be allocated to the specified OSD. For example, to configure the OSD with ID 8 to use up to 16 GBytes of memory:

    Example 

    [ceph: root@host01 /]# ceph config set osd.8 osd_memory_target 16G

  3. To set an individual OSD to use one maximum amount of memory and configure the rest of the OSDs to use another amount, specify the individual OSD first:

    Example 

    [ceph: root@host01 /]# ceph config set osd osd_memory_target 16G
[ceph: root@host01 /]# ceph config set osd.8 osd_memory_target 8G

Reference