QNAP NAS Error Code 56: How to Fix It

Easy 30 minutes to monitor and manage; scrub itself may take several hours to days depending on array size Medium Severity Verified June 2026
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Error Code
56
Brand
QNAP
Product Type
nas
Severity
Medium
DIY Difficulty
Easy
Estimated Fix Time
30 minutes to monitor and manage; scrub itself may take several hours to days depending on array size
QNAP NAS Error Code 56 indicates that a RAID scrub operation is currently running on your device. A RAID scrub is a routine data integrity check that scans all drives in your array for inconsistencies, bad sectors, or data corruption — and attempts to repair any issues it finds. This is generally a normal and healthy process, but it can affect NAS performance and may signal underlying drive health concerns if errors are discovered during the scrub.
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Tools You'll Need

How to Fix Error Code 56

  1. Confirm the RAID Scrub Status in QTS

  2. Check System Logs for Drive Errors

  3. Run a SMART Test on All Installed Drives

    Do not power off the NAS or remove drives while the RAID scrub or SMART test is in progress. Interrupting these processes could result in data corruption or RAID degradation.

  4. Allow the Scrub to Complete Naturally

  5. Pause or Reschedule the Scrub if Needed

  6. Review and Act on Scrub Results After Completion

    If the scrub report shows unrecoverable errors, treat this as an urgent warning. Back up all critical data before taking any further action, as a failing drive could lead to data loss.

  7. Replace a Failing Drive if Identified

    Always power down the NAS before physically removing or replacing a drive, unless your QNAP model explicitly supports hot-swapping for your specific RAID type. Check your model's documentation before hot-swapping.

Parts You May Need

Replacement hard disk drive (HDD) or solid-state drive (SSD)
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Replacement hard disk drive (HDD) or solid-state drive (SSD)
Check Price on Amazon
Replacement hard disk drive (HDD) or solid-state drive (SSD)
Check Price on Amazon
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When to Call a Professional

Contact QNAP support or a qualified NAS technician if: the scrub fails to complete after multiple attempts, multiple drives are flagged as failing simultaneously, the RAID volume goes into a degraded or failed state, QTS becomes unresponsive during the scrub, or you are unable to access your data after the scrub completes. If you manage business-critical data and are unsure about the results of the scrub report, a professional data recovery or IT service provider should be consulted before attempting any drive replacements.

Frequently Asked Questions

Is QNAP error code 56 serious?
Not necessarily. Error code 56 simply means a RAID scrub is in progress, which is a routine and healthy maintenance operation. It becomes a concern only if the scrub discovers errors it cannot repair, or if a specific drive is flagged as failing during the process. Monitor your system logs and SMART data to determine whether action is needed.
How long does a QNAP RAID scrub take?
The duration depends on the total size of your volume and the speed of your drives. A small array (2–4TB) might complete in a few hours, while a large array (20TB+) can take one to three days. You can monitor progress as a percentage in 'Storage & Snapshots' within QTS.
Can I use my QNAP NAS normally while a RAID scrub is running?
Yes, you can continue using your NAS during a scrub, but expect reduced read/write performance — sometimes significantly so. For best results, pause the scrub during peak usage hours and resume it during off-peak times such as nights or weekends using the scrub scheduling feature in QTS.
How often should I run a RAID scrub on my QNAP NAS?
QNAP recommends running a RAID scrub at least once a month for optimal data integrity. You can automate this by setting a scrubbing schedule in 'Storage & Snapshots' > 'Global Settings' > 'Scrubbing Schedule'. Monthly scrubs help catch drive degradation early before it leads to data loss.
What happens if the QNAP RAID scrub finds errors it cannot fix?
If the scrub finds unrecoverable errors, it means one or more drives in your array have bad sectors that cannot be repaired automatically. This is a serious warning sign. You should immediately back up all data to a separate storage device, run a full SMART test on all drives to identify the failing unit, and replace any problematic drive as soon as possible to prevent total data loss.

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