RAID Capacity Calculator

Warning: The Number of drives per RAID group value was adjusted to meet the requirement for the minimum number of disks per group for this type of RAID.

RAID-Z2 Capacity Calculation:
Total usable storage capacity (TB):	1.00 ^*
RAID type:	RAID-Z2 (double parity with variable stripe width)
Number of RAID groups:	1
Number of drives per RAID group:	4
Total number of drives:	4
Drive capacity (GB):	500
Capacity of a single RAID group (GB):	1000
Space efficiency:	0.5 (50%)
Fault tolerance:	2 disk drives per RAID group
Minimum number of disks drives per RAID-Z2 group:	4
Single drive cost:
Cost per TB usable:
Total cost:

RAID-Z is a software-based RAID implementation in the ZFS file system.
A number of disks, partitions, or even files can be grouped into a raidz group with one of the following parity protection schemas: single parity - RAID-Z1, double parity - RAID-Z2, or triple parity - RAID-Z3. One or multiple raidz groups form a zpool which is used as a storage pool for a ZFS file system. Data is striped across all raidz groups included in a zpool.

^* A raidz group with N disks of size X with P parity disks can hold approximately (N-P)*X bytes. Furthermore, ZFS reserves 1/32 (3.125%) of the available zpool storage capacity. For more details see ZFS / RAIDZ Capacity Calculator

Note: 1 TB = 1000 GB and 1 TiB = 1024 GiB

About:

This calculator computes RAID capacity characteristics for the most commonly used RAID types.

Provide the following parameters: the RAID type, the disk capacity in GB, the number of disks drives per RAID group and the number of RAID groups (if your storage system consists of more than one RAID group of the same configuration).
To perform calculation click Submit.

Optionally, enter the single disk cost to calculate the total storage cost and the cost per TB of usable capacity.

Supported RAID levels are:

RAID 0 (block-level striping without parity or mirroring);
RAID 1 (mirroring without parity or striping);
RAID 1E (mirroring with striping);
3-Way Mirror or Triple Mirror (mirroring without parity or striping);
RAID 3 (byte-level striping with a dedicated parity disk);
RAID 4 (block-level striping with a dedicated parity disk);
RAID 5 (block-level striping with distributed parity);
RAID 5E (RAID 5 Enhanced) and RAID 5EE (RAID 5E Enhanced) (block-level striping with distributed parity and integrated active distributed hot-spare);
RAID 6 (block-level striping with double distributed parity);
RAID 10 (1+0) (striped mirrors - a combination of multiple RAID 1 groups with RAID 0);
RAID 50 (combination of multiple RAID 5 groups with RAID 0);
RAID 60 (combination of multiple RAID 6 groups with RAID 0);
RAID-DP (stripe set with double parity and two dedicated parity disks);
RAID-TEC (triple erasure encoding);
RAID-Z1 (single parity with variable stripe width);
RAID-Z2 (double parity with variable stripe width);
RAID-Z3 (triple parity with variable stripe width).