+`hdsize`::
+
+Defines the total hard disk size to be used. This is useful to save free space
+on the hard disk(s) for further partitioning (for example to create a
+swap-partition). `hdsize` is only honored for bootable disks, that is only the
+first disk or mirror for RAID0, RAID1 or RAID10, and all disks in RAID-Z[123].
+
+
+ZFS Performance Tips
+~~~~~~~~~~~~~~~~~~~~
+
+ZFS works best with a lot of memory. If you intend to use ZFS make sure to have
+enough RAM available for it. A good calculation is 4GB plus 1GB RAM for each TB
+RAW disk space.
+
+ZFS can use a dedicated drive as write cache, called the ZFS Intent Log (ZIL).
+Use a fast drive (SSD) for it. It can be added after installation with the
+following command:
+
+----
+# zpool add <pool-name> log </dev/path_to_fast_ssd>
+----