Block device input and output options

rbd_compression_hint

Description
Hint to send to the OSDs on write operations. If set to compressible and the OSD bluestore_compression_mode setting is passive, the OSD attempts to compress data. If set to incompressible and the OSD bluestore_compression_mode setting is aggressive, the OSD will not attempt to compress data.

Type
Enum

Required
No

Default
none

Values
none, compressible, incompressible

rbd_read_from_replica_policy

Description
Policy for determining which OSD receives read operations. If set to default, each PG’s primary OSD will always be used for read operations. If set to balance, read operations will be sent to a randomly selected OSD within the replica set. If set to localize, read operations will be sent to the closest OSD as determined by the CRUSH map and the crush_location configuration option, where the crush_location is denoted using key=value. The key aligns with the CRUSH map keys.

NOTE: This feature requires the storage cluster to be configured with a minimum compatible OSD release of the latest version of IBM Storage Ceph.

Type
Enum

Required
No

Default
default

Values
default, balance, localize