Availability choice
RAID Protection Decision Tool
Shortlist a generic mirror or parity approach from your drive count, availability priority, and backup status.
Protection shortlist
Trade-offs and next steps
| Choice | Result | Reason |
|---|
Important warning
RAID is not a backup
Array protection can reduce downtime after a drive failure. It does not create an independently recoverable copy for deletion, corruption, ransomware, theft, or a site event.
Next steps
Validate capacity in the RAID Capacity Calculator, then read RAID Is Not a Backup before adopting an operating procedure.
Decision guide
Use RAID Protection Decision Tool with confidence
This guide explains the protection priority decision behind RAID Protection Decision Tool, the evidence worth collecting for drive count and availability, and the boundaries of its RAID starting shortlist. Work through RAID Protection Decision Tool after a first run, then revise acceptable outage risk until the output reflects realistic conditions rather than convenience.
What this tool helps you decide
Shortlist a generic mirror or parity approach from drive count, availability priority, and independent-backup status. The RAID Protection Decision Tool turns that protection priority question into a vendor-neutral RAID starting shortlist, not a product endorsement. Use RAID Protection Decision Tool before requesting quotes, because acceptable outage risk can change the sensible drive count and availability choice. Keep that scope visible whenever the RAID starting shortlist is compared with alternatives.
Before you start
State available drive count, whether the priority is capacity, availability, or simplicity, and whether an independent backup already exists. Answer the backup question literally. For RAID Protection Decision Tool, write the protection priority assumption beside every saved result. That RAID starting shortlist record lets another person reproduce the drive count and availability scenario, challenge acceptable outage risk, and rerun RAID Protection Decision Tool after conditions change. Test one conservative protection priority case and one demanding case, then compare their RAID starting shortlist range.
How the calculation or recommendation works
The selector starts with mirrors below three drives, favors dual parity for availability when four or more drives exist, and otherwise suggests single parity. It then overlays an explicit independent-backup warning. The RAID Protection Decision Tool keeps protection priority arithmetic transparent, allowing the RAID starting shortlist to be checked without a vendor account. In RAID Protection Decision Tool, follow every drive count and availability unit shown by RAID Protection Decision Tool. Decimal TB and TiB answer capacity questions. Keep every RAID Protection Decision Tool input in its displayed unit; preserve those RAID Protection Decision Tool labels when sharing or checking the result. Round the RAID starting shortlist upward only after reviewing the unrounded RAID Protection Decision Tool result.
How to interpret the results
The recommendation is a shortlist for generic tolerance, not proof that one layout is universally safer. Read tolerated failures with minimum drive count and backup status; a protection result never closes a recovery gap. Read the RAID Protection Decision Tool summary with its protection priority metrics. Use the RAID Protection Decision Tool table and caution note to examine the complete drive count and availability tradeoff. Save acceptable outage risk inputs with the result, compare scenarios under the same protection priority definition, and investigate conflicting RAID starting shortlist output before acting.
Worked example
Four drives, an availability priority, and no independent backup lead to dual parity as the starting shortlist plus a prominent instruction to add a separate recoverable copy before trusting the array. This RAID Protection Decision Tool example demonstrates the protection priority path, not a universal default. Change acceptable outage risk one input at a time, observe which drive count and availability output moves, and note whether the RAID starting shortlist remains stable. Sensitivity around protection priority is more useful than copying another person’s final number.
Assumptions and limitations
The rules do not model unrecoverable read errors, correlated failures, rebuild duration, performance, vendor RAID variants, filesystem checksums, hot spares, or business impact. They cannot certify a deployment. The RAID Protection Decision Tool is a planning aid for drive count and availability in RAID Protection Decision Tool. Treat the protection priority assumptions as boundaries: the RAID starting shortlist supports protection priority planning only. It does not certify an implementation of RAID Protection Decision Tool, guarantee recovery, or provide financial advice. Recheck acceptable outage risk, documentation relevant to RAID Protection Decision Tool, and operating requirements before purchasing for RAID Protection Decision Tool, migrating data, or approving a policy.
Next steps
Use the shortlist to compare capacity tradeoffs, confirm supported layouts, document backup and restore ownership, and test failure notifications before the storage becomes the only copy of important data. Continue from RAID Protection Decision Tool to the Why RAID Is Not a Backup, then carry the RAID Protection Decision Tool finding into another nas configuration tool for the next RAID Protection Decision Tool drive count and availability decision. Keep the RAID Protection Decision Tool RAID starting shortlist with its assumptions. Record the decision date for RAID Protection Decision Tool; assign a reviewer and a dated measurement checkpoint.