Configure a ZFS volume for Time Machine on NAS

Preparation

A ZFS pool should surely pre-exist there to allow for the operations introduced later.

• Key point: Why not split, or shrink existing volumes for a Time Machine volume?

  Not viable. A ZFS partition always tries to occupy as much space as possible, so does ZFS volumes under it, sharing the entire space of it. To reserving some space is exactly what the quota property is designed for.

  In addition, you can use the reservation property to guarantee that a specified amount of disk space is available to a file system. Both properties apply to the dataset on which they are set and all descendents of that dataset.

  More…

• Creating a new ZFS filesystem

  zfs create -o compression=lz4 pool/filesystem

  where the purpose of an optional argument -o compression=lz4 is to turn on the compression for this dataset.