5.5.3. Altering the BlueStore block.db size when you use ceph-volume

A block.db is a database that consists of data segments and BlueStore write-ahead logs (WAL). Use the following procedure to override the block.db size when you use ceph-volume. ceph-volume is used when osd_scenario: lvm. ceph-volume automatically sets the block.db size. However, you can override the block.db size for advanced scenarios.

The following example uses a ceph-ansible host variable, not a Ceph configuration file override, so that the block_db_size that is used is passed to the ceph-volume call.

Procedure

  1. Create a JSON environment file with content similar to the following but replace the values according to your requirements:

    {
      "parameter_defaults": {
        "NodeDataLookup": {
          "32e87b4c-c4a7-41be-865b-191684a6883b": {
            "block_db_size": 3221225472
          },
          "ea6a84d6-cf89-4fe2-b7bd-869b3fe4dd6b": {
            "block_db_size": 3221225472
          }
        }
      }
    }
  2. Include the JSON file with any other environment files that are relevant to your environment when you deploy the overcloud:

    $ openstack overcloud deploy \
    --templates \
    …
    -e <existing_overcloud_environment_files> \
    -e <json_environment_file>  \
    …