projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 11fdf7f2 | 1 | Local Pool Module |
| 3efd9988 FG |
2 | ================= |
| 3 | ||
| 11fdf7f2 | 4 | The *localpool* module can automatically create RADOS pools that are |
| 3efd9988 | 5 | localized to a subset of the overall cluster. For example, by default, it will |
| f67539c2 TL |
6 | create a pool for each distinct ``rack`` in the cluster. This can be useful for |
| 7 | deployments where it is desirable to distribute some data locally and other data | |
| 8 | globally across the cluster. One use-case is measuring performance and testing | |
| 9 | behavior of specific drive, NIC, or chassis models in isolation. | |
| 3efd9988 FG |
10 | |
| 11 | Enabling | |
| 12 | -------- | |
| 13 | ||
| 14 | The *localpool* module is enabled with:: | |
| 15 | ||
| 16 | ceph mgr module enable localpool | |
| 17 | ||
| 18 | Configuring | |
| 19 | ----------- | |
| 20 | ||
| 21 | The *localpool* module understands the following options: | |
| 22 | ||
| 23 | * **subtree** (default: `rack`): which CRUSH subtree type the module | |
| 24 | should create a pool for. | |
| 25 | * **failure_domain** (default: `host`): what failure domain we should | |
| 26 | separate data replicas across. | |
| 27 | * **pg_num** (default: `128`): number of PGs to create for each pool | |
| 28 | * **num_rep** (default: `3`): number of replicas for each pool. | |
| 29 | (Currently, pools are always replicated.) | |
| 30 | * **min_size** (default: none): value to set min_size to (unchanged from Ceph's default if this option is not set) | |
| 31 | * **prefix** (default: `by-$subtreetype-`): prefix for the pool name. | |
| 32 | ||
| 33 | These options are set via the config-key interface. For example, to | |
| 34 | change the replication level to 2x with only 64 PGs, :: | |
| 35 | ||
| 11fdf7f2 TL |
36 | ceph config set mgr mgr/localpool/num_rep 2 |
| 37 | ceph config set mgr mgr/localpool/pg_num 64 |