RAID failure triage

Find the RAID failure you are facing before another operation changes it.

Start with what the controller, server, or storage system is showing now. ADR's guidance connects the symptom to the right RAID-level or platform-specific path without requiring the failed array to be brought online.

Call a RAID recovery technician Start emergency triage

If possible, record the server or NAS model, controller model, RAID level, drive count and capacity, original bay order, exact messages, and everything already attempted.

Symptom firstBegin with what the system reports

Member awarePreserve identity and original order

Sources protectedNo writes without an approved plan

Controller optionalThe failed array need not be online

Start with the symptom

You do not need to know the cause before you protect the right evidence.

Choose the closest description. These pages explain what the message may mean, what not to do, what information matters, and when technician review should begin.

Array offlineThe array or virtual disk disappearedThe server cannot see the expected volume, or the controller reports the array as offline or inaccessible.Review an offline array → Multiple-member failureMore than one member is failed, missing, or unstableThe array has exceeded normal fault tolerance, or another member dropped during degraded operation.Review multiple-member failure → Rebuild failedA rebuild stalled, stopped, or produced errorsThe original member and partial rebuild target may preserve different portions of the recoverable state.Review a failed rebuild → Rebuild runningA rebuild has already startedRecord its progress and messages before deciding whether continued reads are helping or compounding damage.Review an active rebuild → Degraded and unstableThe system is dropping members or changing statusRepeated timeouts, intermittent detection, or changing membership can make the available state worse.Review an unstable RAID → Configuration messageThe controller reports foreign or missing configurationDo not import or clear metadata until the full member set and controller history are understood.Begin controller triage →

Choose the RAID level

Each RAID family fails differently and must be reconstructed on its own terms.

If the RAID level is known, continue into the appropriate cluster for focused failure guidance and the correct reconstruction sequence.

Single parityRAID 5Offline arrays, two-member loss, rebuild stalls, missing virtual disks, and parity uncertainty.Open RAID 5 triage → Dual parityRAID 6Multiple failures, intervention risk, rebuild behavior, and conflicting member states.Open RAID 6 triage → Mirrored stripesRAID 10Missing pairs, mirror mismatch, configuration loss, rebuild crashes, and boot failures.Open RAID 10 triage → Nested parityRAID 50Lower RAID 5 group recovery followed by validation of the stripe joining those groups.Open RAID 50 triage → Nested dual parityRAID 60Lower RAID 6 group reconstruction followed by validation of the compound array.Open RAID 60 triage →

ADR's recovery operating model

The failed controller does not have to decide what happens next.

The server does not need to boot, the volume does not need to mount, and the failed array does not need to be brought online. ADR can begin from separately connected members, protect unstable sources, determine the layout, and reconstruct to separate destination storage.

See how ADR begins recovery Review RAID recovery services

Before another controller operation

Tell ADR what the system shows now.

An ADR technician can review the member count, displayed status, controller messages, actions already taken, business impact, and the safest way to begin.

Call 1-800-228-8800 Start emergency triage