Storage repair
Synology Storage Pool Degraded: Diagnose Before Repair
Synology defines a Degraded storage pool as one where a member drive or related problem has reduced redundancy but the pool remains accessible and no data loss has occurred at that stage. That is a warning window, not permission to continue normal risk-taking. Identify the defective drive, confirm backup, and repair the protected pool before optional upgrades.
Quick answer
Degraded means accessible with protection reduced
Keep the NAS workload light, verify important data can be restored elsewhere, and use Storage Manager plus HDD/SSD status to identify the actual defective member before removing anything.
Live Amazon products
Hardware relevant to this technical workflow
This Sprint 9F catalogue is intentionally focused on current and previous Synology Plus systems. Storage-repair pages can also read compatible third-party NAS hard-drive data from Cloudzat Storage Price Intelligence in read-only mode. Product cards support the decision; they never override current Synology compatibility or model-specific repair rules.
Technical decision
Repair redundancy before optimizing capacity
Do not mix a failed-drive repair with a casual RAID migration or capacity expansion unless the documented procedure specifically requires it.
Interactive technical tool
Degraded Storage Pool Triage Tool
Use this as a planning aid. It identifies capacity, redundancy, deployment or repair constraints, but it does not replace the current Synology model manual, DSM documentation or upstream application release notes.
Technical safety checklist
Four checks before changing a production NAS
Protect data before maintenance
A healthy RAID state is not a backup. Confirm an independent restorable copy before repairs, DSM upgrades, RAID migration or major container changes.
Change one layer at a time
Storage, DSM, networking and application changes should be separated so an unexpected result can be traced to one action rather than several.
Record the exact state
Write down model, DSM build, pool type, drive serials, ports, mapped folders and current application versions before modifying a production NAS.
Verify the result
A repair or upgrade is complete only after storage health, services, backups and representative restores behave as expected.
Degraded is not the same as crashed
Degraded is not the same as crashed is central to Synology Storage Pool Degraded: Synology describes Degraded as an accessible pool whose data protection has been reduced by a defective drive or similar issue. For Synology Storage Pool Degraded, record the degraded-pool path baseline before action. When checking degraded is not the same as crashed, compare the degraded-pool path result with that earlier degraded-pool path baseline.
A tested backup protects the degraded-pool path workflow during degraded is not the same as crashed. For Synology Storage Pool Degraded, recovery of the degraded-pool path state matters more than speed.
Confirm the exact failing member
For Synology Storage Pool Degraded, confirm the exact failing member matters because Storage Manager and the HDD/SSD page should identify which device is defective before a physical disk is removed. For Synology Storage Pool Degraded, record the degraded-pool path baseline before action. When checking confirm the exact failing member, compare the degraded-pool path result with that earlier degraded-pool path baseline.
Document the degraded-pool path decision around confirm the exact failing member. In Synology Storage Pool Degraded, record why the degraded-pool path state changed and what outcome the degraded-pool path procedure expects.
Back up important data before repair
Inside Synology Storage Pool Degraded, the practical constraint is this: a degraded one-drive-tolerant pool may have no remaining margin for a second member failure during the rebuild. For Synology Storage Pool Degraded, record the degraded-pool path baseline before action. When checking back up important data before repair, compare the degraded-pool path result with that earlier degraded-pool path baseline.
Keep back up important data before repair separate from other degraded-pool path changes. On Synology Storage Pool Degraded, isolating the degraded-pool path work makes a failure in the degraded-pool path path easier to identify.
Use a healthy compatible replacement
The Synology Storage Pool Degraded reason to study use a healthy compatible replacement is straightforward: Synology recommends compatible drives and defines replacement-size requirements according to the current RAID type and failed member. For Synology Storage Pool Degraded, record the degraded-pool path baseline before action. When checking use a healthy compatible replacement, compare the degraded-pool path result with that earlier degraded-pool path baseline.
Before buying hardware for use a healthy compatible replacement, decide whether the degraded-pool path target is capacity, redundancy or availability; verify the resulting degraded-pool path outcome directly.
Hot swap is hardware-specific
Synology Storage Pool Degraded planning can fail here because if the exact DiskStation does not support hot swapping, power it off before drive removal and installation. For Synology Storage Pool Degraded, record the degraded-pool path baseline before action. When checking hot swap is hardware-specific, compare the degraded-pool path result with that earlier degraded-pool path baseline.
In Synology Storage Pool Degraded, make the degraded-pool path step reversible. Back up the degraded-pool path state; change one variable for hot swap is hardware-specific; verify the degraded-pool path result before continuing.
The Repair feature applies only to protected layouts
A safer Synology Storage Pool Degraded interpretation starts with one fact: Synology lists RAID 1, RAID 5, RAID 6, RAID 10, RAID F1 and qualifying SHR pools among the layouts that can use repair. For Synology Storage Pool Degraded, record the degraded-pool path baseline before action. When checking the repair feature applies only to protected layouts, compare the degraded-pool path result with that earlier degraded-pool path baseline.
If a tutorial conflicts with the degraded-pool path behavior on Synology Storage Pool Degraded, stop at the repair feature applies only to protected layouts; follow the model-specific Synology instructions for the degraded-pool path condition.
SHR-2 replacement rules are different
SHR-2 replacement rules are different is central to Synology Storage Pool Degraded: two-drive-tolerant SHR can accept a replacement based on the failed drive size or the fourth-largest drive criterion documented by Synology. For Synology Storage Pool Degraded, record the degraded-pool path baseline before action. When checking shr-2 replacement rules are different, compare the degraded-pool path result with that earlier degraded-pool path baseline.
A tested backup protects the degraded-pool path workflow during shr-2 replacement rules are different. For Synology Storage Pool Degraded, recovery of the degraded-pool path state matters more than speed.
A hot spare may start repair automatically
For Synology Storage Pool Degraded, a hot spare may start repair automatically matters because supported RAID Group systems can use assigned spares, although Synology notes that Auto Repair is not supported on SHR storage pools. For Synology Storage Pool Degraded, record the degraded-pool path baseline before action. When checking a hot spare may start repair automatically, compare the degraded-pool path result with that earlier degraded-pool path baseline.
Document the degraded-pool path decision around a hot spare may start repair automatically. In Synology Storage Pool Degraded, record why the degraded-pool path state changed and what outcome the degraded-pool path procedure expects.
Do not deactivate the wrong disk
Inside Synology Storage Pool Degraded, the practical constraint is this: labels, serial numbers, bay numbers and DSM status should be reconciled before touching hardware. For Synology Storage Pool Degraded, record the degraded-pool path baseline before action. When checking do not deactivate the wrong disk, compare the degraded-pool path result with that earlier degraded-pool path baseline.
Keep do not deactivate the wrong disk separate from other degraded-pool path changes. On Synology Storage Pool Degraded, isolating the degraded-pool path work makes a failure in the degraded-pool path path easier to identify.
Rebuild completion is not the end
The Synology Storage Pool Degraded reason to study rebuild completion is not the end is straightforward: after repair, review drive health, storage logs, backup status and any application errors caused during the degraded period. For Synology Storage Pool Degraded, record the degraded-pool path baseline before action. When checking rebuild completion is not the end, compare the degraded-pool path result with that earlier degraded-pool path baseline.
Before buying hardware for rebuild completion is not the end, decide whether the degraded-pool path target is capacity, redundancy or availability; verify the resulting degraded-pool path outcome directly.
Repeated failures may indicate a broader problem
Synology Storage Pool Degraded planning can fail here because multiple disks reporting faults can point to age, power, backplane or environmental issues rather than a single unlucky drive. For Synology Storage Pool Degraded, record the degraded-pool path baseline before action. When checking repeated failures may indicate a broader problem, compare the degraded-pool path result with that earlier degraded-pool path baseline.
In Synology Storage Pool Degraded, make the degraded-pool path step reversible. Back up the degraded-pool path state; change one variable for repeated failures may indicate a broader problem; verify the degraded-pool path result before continuing.
A repair is not a backup restore test
A safer Synology Storage Pool Degraded interpretation starts with one fact: once the pool is healthy, still restore sample files from the independent backup so the next incident does not reveal an untested recovery plan. For Synology Storage Pool Degraded, record the degraded-pool path baseline before action. When checking a repair is not a backup restore test, compare the degraded-pool path result with that earlier degraded-pool path baseline.
If a tutorial conflicts with the degraded-pool path behavior on Synology Storage Pool Degraded, stop at a repair is not a backup restore test; follow the model-specific Synology instructions for the degraded-pool path condition.
Questions people ask
Synology Storage Pool Degraded: common questions
What does Degraded mean on Synology?
It means redundancy is reduced but the storage pool remains accessible at that stage.
For Synology Storage Pool Degraded, "What does Degraded mean on Synology?" depends on the degraded-pool path: check the exact DSM build for the degraded-pool path, the NAS model, and the current degraded-pool path state.
Is my data already lost?
Synology’s Degraded definition says the pool remains accessible without data loss at that point, but the risk is higher until repaired.
For Synology Storage Pool Degraded, "Is my data already lost?" depends on the degraded-pool path: check the exact DSM build for the degraded-pool path, the NAS model, and the current degraded-pool path state.
Can I keep using the NAS?
Use it cautiously and prioritize backup and repair because redundancy is reduced.
For Synology Storage Pool Degraded, "Can I keep using the NAS?" depends on the degraded-pool path: check the exact DSM build for the degraded-pool path, the NAS model, and the current degraded-pool path state.
Which drive should I replace?
Use Storage Manager and HDD/SSD status to identify the defective member by bay and serial number.
For Synology Storage Pool Degraded, "Which drive should I replace?" depends on the degraded-pool path: check the exact DSM build for the degraded-pool path, the NAS model, and the current degraded-pool path state.
Can I use a larger replacement drive?
Usually yes if it satisfies the RAID-type replacement rules, but verify the exact Synology requirements.
For Synology Storage Pool Degraded, "Can I use a larger replacement drive?" depends on the degraded-pool path: check the exact DSM build for the degraded-pool path, the NAS model, and the current degraded-pool path state.
Can I use a smaller replacement drive?
Only if it meets the pool-specific size rule; do not assume a physically smaller-capacity drive can repair the array.
For Synology Storage Pool Degraded, "Can I use a smaller replacement drive?" depends on the degraded-pool path: check the exact DSM build for the degraded-pool path, the NAS model, and the current degraded-pool path state.
Should I power off before replacement?
Power off if the exact NAS does not support hot swapping.
For Synology Storage Pool Degraded, "Should I power off before replacement?" depends on the degraded-pool path: check the exact DSM build for the degraded-pool path, the NAS model, and the current degraded-pool path state.
How long will repair take?
Duration varies with drive size, workload, hardware and storage state. Do not plan around a universal rebuild time.
For Synology Storage Pool Degraded, "How long will repair take?" depends on the degraded-pool path: check the exact DSM build for the degraded-pool path, the NAS model, and the current degraded-pool path state.
Can Auto Repair fix SHR?
Synology notes that Auto Repair is not supported on SHR storage pools.
For Synology Storage Pool Degraded, "Can Auto Repair fix SHR?" depends on the degraded-pool path: check the exact DSM build for the degraded-pool path, the NAS model, and the current degraded-pool path state.
What if more than one drive failed?
Stop and assess the RAID level and backup before replacing drives blindly. The tolerated failure count may already be exceeded.
For Synology Storage Pool Degraded, "What if more than one drive failed?" depends on the degraded-pool path: check the exact DSM build for the degraded-pool path, the NAS model, and the current degraded-pool path state.
Official references and methodology
Verify the exact model, DSM build and application state
This Synology Storage Pool Degraded guide uses primary documentation for the degraded-pool path. Cloudzat evaluates the degraded-pool path capacity, redundancy, deployment and recovery layers separately. Interactive degraded-pool path results support planning; final degraded-pool path changes need exact model guidance and current upstream documentation.
- Synology: Repair a storage pool
- Synology: Replace a drive / expand storage capacity
- Synology: What is Synology Hybrid RAID (SHR)?
- Synology: What RAID type is best for my storage?
As an Amazon Associate, Cloudzat may earn from qualifying purchases. Prices, NAS models, drive compatibility, DSM behavior and upstream application requirements can change. Verify the exact DiskStation model, current DSM documentation and application release notes before changing storage pools, replacing drives, exposing network services or upgrading production containers.