This guide assumes that your undercloud is already installed and ready to deploy an overcloud.
Ceph demands for more careful configuration when deployed at scale.
It is possible to override any of the configuration parameters supported by puppet-ceph at deployment time via Heat environment files. For example:
parameter_defaults: ExtraConfig: ceph::profile::params::osd_journal_size: 2048
will customize the default osd_journal_size overriding any default provided in the ceph.yaml static hieradata.
Remember to add such an environment file to the deploy commandline:
openstack overcloud deploy --templates --ceph-storage-scale <number of nodes> -e /usr/share/openstack-tripleo-heat-templates/environments/storage-environment.yaml -e ~/my-ceph-settings.yaml
It is also possible to provide arbitrary stanza/key/value lines for ceph.conf using the special ceph::conf configuration class. For example by using:
parameter_defaults: ExtraConfig: ceph::conf::args: global/max_open_files: value: 131072 global/my_setting: value: my_value
the resulting ceph.conf file should be populated with the following:
[global] max_open_files: 131072 my_setting: my_value
The Node customization and Third-Party Integration doc has a more details on the usage of the different ExtraConfig interfaces.