The `datavol.yml` playbook can provision one or more data volumes on
a managed node, using the definitions in the `data_volumes` variable.
This variable must contain a list of dictionaries with the following
keys:
* `dev`: The block device where the data volume is stored (e.g.
`/dev/vdb`)
* `fstype`: The type of filesystem to create on the block device
* `mountpoint`: The location in the filesystem hierarchy where the
volume is mounted
* `opts`: (Optional) options to pass to the `mkfs` program when
formatting the device
* `mountopts`: (Optional) additional options to pass to the `mount`
program when mounting the filesystem