I am currently setting up a FreeNAS server to be a backup point for a number of computers/devices. It contains 12x 4TB HDD's, in one large RaidZ2. The total gross disk size for the volume is about 41 TB, with about 33TB as shown in FreeNAS that is available to create datasets with.
However, 3.63 TB x 12 HDD's = 43.56 TB, minus 7.26 TB for 2 parity drives = 36.3 TB. Why am I only seeing about 33TB of usable space? Are there any tweaks I can make during volume creation to gain back some of the space? Speed is not a concern, but maximizing space with RaidZ2 is. Any ideas? Ashift settings?
However, 3.63 TB x 12 HDD's = 43.56 TB, minus 7.26 TB for 2 parity drives = 36.3 TB. Why am I only seeing about 33TB of usable space? Are there any tweaks I can make during volume creation to gain back some of the space? Speed is not a concern, but maximizing space with RaidZ2 is. Any ideas? Ashift settings?