-= Hard Drive & RAID Cost Calculator =-

DRIVE INPUTS:

RAID SETUP:

CONFIG MANAGER:

RAID Type Info:

None (Individual Drives)

Each drive is treated as a separate storage unit. This mode is for comparing the cost-effectiveness of individual drives.

  • Pros: Simple, full capacity of each drive is usable.
  • Cons: No data redundancy, no performance increase from array. Failure of one drive means data on that drive is lost.

RAID 0 (Striping)

Combines multiple drives into a single larger, faster volume by writing data across drives in "stripes".

  • Minimum Drives: 2
  • Usable Capacity: Sum of all drive capacities.
  • Pros: Increased performance (read/write speed). Full capacity utilization.
  • Cons: No fault tolerance. If one drive fails, all data in the array is lost.

RAID 1 (Mirroring)

Writes identical data to two or more drives simultaneously, creating a "mirror".

  • Minimum Drives: 2
  • Usable Capacity: Capacity of the smallest drive (or total capacity / number of drives if all are same size and setup is simple mirror). For this calculator with potentially mixed sizes, we use Total Raw / 2 for a basic 2-drive mirror concept, or smallest for N-way. For simplicity, we'll assume Total Raw / 2.
  • Pros: High fault tolerance (data survives if one drive fails). Good read performance.
  • Cons: Low capacity utilization (50% of total raw capacity). Write performance can be slower.

RAID 5 (Single Parity)

Stripes data and parity information across three or more drives. Provides a balance of performance, capacity, and redundancy.

  • Minimum Drives: 3
  • Usable Capacity: (Number of Drives - 1) × Capacity of Smallest Drive.
  • Pros: Good read performance, decent write performance. Fault tolerance (can withstand failure of one drive). Efficient capacity usage compared to RAID 1.
  • Cons: Write performance can be slower due to parity calculation. Rebuild times can be long if a drive fails.

RAID 6 (Dual Parity)

Similar to RAID 5, but uses two independent parity blocks. Can withstand the failure of two drives simultaneously.

  • Minimum Drives: 4
  • Usable Capacity: (Number of Drives - 2) × Capacity of Smallest Drive.
  • Pros: Higher fault tolerance than RAID 5. Good read performance.
  • Cons: Slower write performance than RAID 5 due to dual parity calculations. Lower capacity utilization than RAID 5. Longer rebuild times.

RAID 10 (Stripe of Mirrors / RAID 1+0)

Combines mirroring and striping. Data is first mirrored onto pairs of drives, and then these mirrored pairs are striped together.

  • Minimum Drives: 4 (must be an even number)
  • Usable Capacity: Total Raw Capacity / 2.
  • Pros: Good performance (both read and write) and good fault tolerance (can withstand failure of one drive in each mirrored pair).
  • Cons: Lower capacity utilization (50% of total raw capacity). Requires more drives.

RAID-Z1 (Single Parity - ZFS)

ZFS equivalent of RAID 5. Uses variable stripe width and copy-on-write, offering better data integrity and protection against write holes compared to traditional RAID 5.

  • Minimum Drives: 3 (recommended for parity)
  • Usable Capacity: (Number of Drives - 1) × Capacity of Smallest Drive. (Note: ZFS has a small metadata overhead not accounted for here, but this is a common estimation. For performance, keeping usage under 80% of this value is often recommended.)
  • Pros: Good data integrity, protection against write holes, efficient capacity. Can withstand failure of one drive.
  • Cons: Performance can degrade with many small files. Adding drives to expand an existing RAID-Z1 vdev is complex (often requires replacing all drives or adding a new vdev).

RAID-Z2 (Dual Parity - ZFS)

ZFS equivalent of RAID 6. Provides dual parity for increased data protection.

  • Minimum Drives: 4 (recommended for parity)
  • Usable Capacity: (Number of Drives - 2) × Capacity of Smallest Drive. (See 80% note for RAID-Z1)
  • Pros: Excellent data integrity, can withstand failure of two drives.
  • Cons: Higher capacity overhead than RAID-Z1. Expansion complexity similar to RAID-Z1.

RAID-Z3 (Triple Parity - ZFS)

ZFS specific, provides triple parity for very high data protection, suitable for large arrays where rebuild times are long.

  • Minimum Drives: 5 (recommended for parity)
  • Usable Capacity: (Number of Drives - 3) × Capacity of Smallest Drive. (See 80% note for RAID-Z1)
  • Pros: Extremely high data integrity, can withstand failure of three drives.
  • Cons: Highest capacity overhead. Expansion complexity similar to RAID-Z1/Z2.