Parent and child read options

Understand the parent and child read options for Ceph Block Devices.

Table 1 lists the parent and child read options for Ceph Block Device configuration.

Table 1. Parent and child read options

Option	Description	Type	Default
rbd_balance_snap_reads	Ceph typically reads objects from the primary OSD. Since reads are immutable, you can enable this feature to balance snap reads between the primary OSD and the replicas. This option randomizes the replica for reading a snapshot.	Boolean	false
rbd_localize_snap_reads	The block device looks to the CRUSH map to find the closest or local OSD for reading the snapshot.	Boolean	false
rbd_balance_parent_reads	Ceph typically reads objects from the primary OSD. Since reads are immutable, you can enable this feature to balance parent reads between the primary OSD and the replicas. This option randomizes the replica for reading a parent.	Boolean	false
rbd_localize_parent_reads	The block device looks to the CRUSH map to find the closest or local OSD for reading the parent.	Boolean	true