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QNAP volume unmounted or inactive? What to do

November 1, 2026

QNAP NAS boxes are popular with small offices and home users across the UK because they keep files in one place and protect them against a single disk failure. That protection has limits, though. If you have opened Storage & Snapshots in QTS or QuTS hero and found a storage pool or volume marked Unmounted, Not active, Inactive or Error, your shared folders have probably disappeared too. This guide explains what those warnings usually mean, what is safe to do, and which “fixes” put your data at risk.

What the warning means

A QNAP NAS builds your storage in layers. The disks are combined into a RAID group, the RAID group forms a storage pool, and volumes sit inside the pool. Your shared folders live on those volumes. A warning at any layer stops everything above it from working:

  • Degraded means a disk has failed or dropped out, but the RAID group can still run on the remaining disks. The data is usually still readable, but there is no spare protection left.
  • Not active, Inactive or Error on a pool or RAID group usually means the NAS cannot assemble it, often because more disks have dropped out than the RAID level can cope with.
  • Unmounted on a volume often means the RAID group is present but the file system on top of it could not be mounted, for example after a sudden power cut.

Common causes

  • A second disk failing while the NAS was already degraded, or during a rebuild.
  • A power cut or forced shutdown during heavy writing.
  • A disk with bad sectors being kicked out of the array, even though it still spins.
  • Disks removed, swapped or put back in a different order.
  • Problems appearing after a firmware update or restart, which often reveal a disk fault that was already there.

Safe first steps

  1. Stop writing to the NAS. Ask everyone to stop saving files to it, and pause backup jobs, sync tasks and cameras that record to it.
  2. Write down what you see. Take screenshots of Storage & Snapshots, the status of each disk and which bay it is in, and the system logs. This information is very useful later.
  3. Leave the disks where they are. Do not pull disks out or change their order. If the unit must be moved, label each disk with its bay number first.
  4. Check your backups. If you have an up-to-date copy elsewhere, such as an external drive or cloud backup, confirm it is complete before anything else is tried on the NAS.
  5. Shut down cleanly if disks are failing. If disk status shows warnings, or you hear clicking, shut the NAS down from the menu and leave it off.

What not to do

  • Do not remove the pool or volume and create a new one. It may look like a quick way to get the NAS working again, but it overwrites the structures needed to rebuild your data.
  • Do not initialise disks or reinstall the system in a way that offers to reformat them.
  • Do not force a rebuild onto a new disk while other disks are showing errors. A rebuild reads every sector of the remaining disks and is a common point at which a second weak disk fails.
  • Do not run file system repairs over and over. A check on an array with failing disks adds strain and can make changes that are hard to undo.
  • Do not connect the disks to a Windows PC. Windows cannot read the QNAP layout and may offer to initialise the disks, which would overwrite them.

When files are present but will not open

If the volume mounts but your files have strange extensions or there is a ransom note, the problem is likely ransomware rather than a disk failure. Disconnect the NAS from the network and do not delete anything, as the evidence and any snapshots may help the recovery.

How the data is recovered

A safe recovery starts by copying each disk, sector by sector, onto healthy storage. Disks with physical faults are dealt with first so they can be read. The RAID group is then rebuilt virtually from the copies, the volume layer is reassembled and the files are extracted. The original disks are not written to at any stage. You can read more on our QNAP NAS data recovery and NAS data recovery pages.

Talk to us

If your QNAP storage pool or volume has stopped working and the data matters, call Data Retrieval on 020 7064 4996 or request a quote. We offer a free assessment, with no obligation.