Specifying maximum OSD capacity

You can override the maximum Ceph OSD capacity automatically set during OSD initialization.

These steps are optional. Perform the following steps if the default capacity does not accurately represent the Ceph OSD capacity.

Note: Ensure that you determine the benchmark data first, as described in manually benchmarking OSDs.

Prerequisites

  • A running IBM Storage Ceph cluster.

  • Root-level access to the Ceph Monitor host.

Procedure

Procedure

  1. Log into the cephadm shell:

    Example

    [root@host01 ~]# cephadm shell

  2. Set osd_mclock_max_capacity_iops_[hdd, ssd] option for an OSD:

    Syntax

    ceph config set osd.OSD_ID osd_mclock_max_capacity_iops_[hdd,ssd] VALUE

    Example

    [ceph: root@host01 /]# ceph config set osd.0 osd_mclock_max_capacity_iops_hdd 350

    This example sets the maximum capacity for osd.0, where an underlying device type is HDD, to 350 IOPS.