Pool values
This information contains key-values pairs that you can set or get.
For further information, see Setting pool values and Getting pool values.
| Value | Description | Type | Required | Default |
|---|---|---|---|---|
| size | Specifies the number of replicas for objects in the pool. See the Setting the number of object replicas section for further details. Applicable for the replicated pools only. | Integer | No | None |
| min_size | Specifies the minimum number of replicas required for I/O. See the Setting the number of object replicas section for further details. For
erasure-coded pools, this should be set to a value greater than k. If I/O is
allowed at the value k, then there is no redundancy and data is lost in the event
of a permanent OSD failure. For more information, see Erasure code pools overview. |
Integer | No | None |
| crash_replay_interval | Specifies the number of seconds to allow clients to replay acknowledged, but uncommitted requests. | Integer | No | None |
| pg_num | The total number of placement groups for the pool. See the Pools, placement groups, and CRUSH configuration options for details on
calculating a suitable number. Note: The default value 8 is not suitable for most
systems. |
Integer | Yes | 8 |
| pgp_num | The total number of placement groups for placement purposes. This should be equal to the
total number of placement groups, except for placement group splitting scenarios. Valid range:
Equal to or less than what specified by the |
Integer | Yes. Picks up default or Ceph configuration value if not specified. | None |
| crush_rule | The rule to use for mapping object placement in the cluster. | String | No | None |
| hashpspool | Enable or disable the HASHPSPOOL flag on a given pool. With this option
enabled, pool hashing and placement group mapping are changed to improve the way pools and placement
groups overlap. Valid settings: Important: Do not enable this option on production pools of a cluster
with a large amount of OSDs and data. All placement groups in the pool would have to be remapped
causing too much data movement. |
Integer | No | None |
| fast_read | On a pool that uses erasure coding, if this flag is enabled, the read request issues
subsequent reads to all shards, and waits until it receives enough shards to decode to serve the
client. In the case of the jerasure and isa erasure plug-ins, once
the first K replies return, the client's request is served immediately using the data decoded from
these replies. This helps to allocate some resources for better performance. Currently this flag is
only supported for erasure coding pools. |
Boolean | No | 0 |
| allow_ec_overwrites | Whether writes to an erasure coded pool can update part of an object, so the Ceph Filesystem and Ceph Block Device can use it. | Boolean | No | None |
| compression_algorithm | Sets inline compression algorithm to use with the BlueStore storage backend. This setting
overrides the bluestore_compression_algorithm configuration setting. Valid
settings: |
String | No | None |
| compression_mode | Sets the policy for the inline compression algorithm for the BlueStore storage backend. This
setting overrides the bluestore_compression_algorithm configuration setting.
Valid settings: |
String | No | None |
| compression_min_blob_size | BlueStore does not compress chunks smaller than this size. This setting overrides the bluestore_compression_min_blob_size configuration setting. | Unsigned Integer | No | None |
| compression_max_blob_size | BlueStore breaks chunks larger than this size into smaller blobs of compression_max_blob_size before compressing the data. | Unsigned Integer | No | None |
| nodelete | Set or unset the NODELETE flag on a given pool. Valid settings:
|
Integer | No | None |
| nopgchange | Set or unset the NOPGCHANGE flag on a given pool. | Integer | No | None |
| nosizechange | Set or unset the NOSIZECHANGE flag on a given pool. Valid settings:
|
Integer | No | None |
| write_fadvise_dontneed | Set or unset the WRITE_FADVISE_DONTNEED flag on a given pool. Valid
settings: |
Integer | No | None |
| noscrub | Set or unset the NOSCRUB flag on a given pool. Valid settings:
|
Integer | No | None |
| nodeep-scrub | Set or unset the NODEEP_SCRUB flag on a given pool. Valid settings:
|
Integer | No | None |
| scrub_min_interval | The minimum interval in seconds for pool scrubbing when load is low. If it is
0, Ceph uses the osd_scrub_min_interval configuration
setting. |
Double | No | 0 |
| scrub_max_interval | The maximum interval in seconds for pool scrubbing irrespective of cluster load. If it is
0, Ceph uses the osd_scrub_max_interval configuration
setting. |
Double | No | 0 |
| deep_scrub_interval | The interval in seconds for pool deep scrubbing. If it is 0,
Ceph uses the osd_deep_scrub_interval configuration setting. |
Double | No | 0 |
| peering_crush_bucket_count | The value is used along with peering_crush_bucket_barrier to determined whether the set of OSDs in the chosen acting set can peer with each other, based on the number of distinct buckets there are in the acting set. | Integer | No | None |
| peering_crush_bucket_target | This value is used along with peering_crush_bucket_barrier and size to calculate the value
bucket_max which limits the number of OSDs in the same bucket from getting chose to
be in the acting set of a PG. |
Integer | No | None |
| peering_crush_bucket_barrier | The type of bucket a pool is stretched across. For example, rack, row, or datacenter. | String | No | None |