The localpool module can automatically create RADOS pools that are localized to a subset of the overall cluster. For example, by default, it will create a pool for each distinct rack in the cluster. This can be useful for deployments where it is desirable to distribute some data locally and other data globally across the cluster. One use-case is measuring performance and testing behavior of specific drive, NIC, or chassis models in isolation.
The localpool module is enabled with:
ceph mgr module enable localpoolThe localpool module understands the following options:
subtree
failure_domain
pg_num
num_rep
min_size
prefix
These options are set via the config-key interface. For example, to change the replication level to 2x with only 64 PGs, :
ceph config set mgr mgr/localpool/num_rep 2
ceph config set mgr mgr/localpool/pg_num 64