Pools

The Ceph Object Gateway uses several pools for its various storage needs, which are listed in the Zone object (see radosgw-admin zone get). A single zone named default is created automatically with pool names starting with default.rgw., but a Multisite Configuration will have multiple zones.

Tuning

When radosgw first tries to operate on a zone pool that does not exist, it will create that pool with the default values from osd pool default pg num and osd pool default pgp num. These defaults are sufficient for some pools, but others (especially those listed in placement_pools for the bucket index and data) will require additional tuning. We recommend using the Ceph Placement Group’s per Pool Calculator to calculate a suitable number of placement groups for these pools. See Pools for details on pool creation.

Pool Namespaces

New in version Luminous.

Pool names particular to a zone follow the naming convention {zone-name}.pool-name. For example, a zone named us-east will have the following pools:

  • .rgw.root
  • us-east.rgw.control
  • us-east.rgw.meta
  • us-east.rgw.log
  • us-east.rgw.buckets.index
  • us-east.rgw.buckets.data

The zone definitions list several more pools than that, but many of those are consolidated through the use of rados namespaces. For example, all of the following pool entries use namespaces of the us-east.rgw.meta pool:

"user_keys_pool": "us-east.rgw.meta:users.keys",
"user_email_pool": "us-east.rgw.meta:users.email",
"user_swift_pool": "us-east.rgw.meta:users.swift",
"user_uid_pool": "us-east.rgw.meta:users.uid",