projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 11fdf7f2 TL |
1 | # Specifying the I/O properties of a system |
| 2 | ||
| 3 | The I/O properties of a system can be specified as a YAML string, by | |
| 4 | using the option --io-properties, or as a YAML file with the option | |
| 5 | --io-properties-file. | |
| 6 | ||
| 7 | The expected format starts with a map of sections at the top level. | |
| 8 | Currently only `disks` is supported. | |
| 9 | ||
| 10 | ## The disks section | |
| 11 | ||
| 12 | Inside the `disks` section, the user can specify a list of mount points. | |
| 13 | ||
| 14 | For each mount point, 4 properties have to be specified (none are | |
| 15 | optional): | |
| 16 | ||
| 17 | * `read_iops`: read IOPS speed of the device | |
| 18 | * `read_bandwidth`: read bandwidth speed of the device | |
| 19 | * `write_iops`: write IOPS speed of the device | |
| 20 | * `write_bandwidth`: write bandwidth speed of the device | |
| 21 | ||
| 20effc67 TL |
22 | |
| 23 | Additionally the following optional properties can be added: | |
| 24 | ||
| 25 | * `read_saturation_length`: read buffer length to saturate the device throughput | |
| 26 | * `write_saturation_length`: write buffer length to saturate the device throughput | |
| 27 | ||
| 11fdf7f2 TL |
28 | Those quantities can be specified in raw form, or followed with a |
| 29 | suffix (k, M, G, or T). | |
| 30 | ||
| 31 | Example: | |
| 32 | ||
| 33 | ``` | |
| 34 | disks: | |
| 35 | - mountpoint: /var/lib/some_seastar_app | |
| 36 | read_iops: 95000 | |
| 37 | read_bandwidth: 545M | |
| 38 | write_iops: 85000 | |
| 39 | write_bandwidth: 510M | |
| 20effc67 | 40 | write_saturation_length: 64k |
| 11fdf7f2 | 41 | ``` |