188.8.131.52. Using dedicated write-ahead log (WAL) devices
You can specify a dedicated write-ahead log (WAL) device. Using
bluestore_wal_devices together means that you can isolate all components of an OSD on to separate devices, which can increase performance.
In the following example procedure, another additional dictionary,
bluestore_wal_devices, isolates the write-ahead log on NVMe devices
Add the following content to an environment file:
parameter_defaults: CephAnsibleDisksConfig: devices: - /dev/sda - /dev/sdb dedicated_devices: - /dev/sdx - /dev/sdy bluestore_wal_devices: - /dev/nvme0n1 - /dev/nvme0n2
Include the environment file that contains your new content in the deployment command with the
-eoption when you deploy the overcloud.