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NDR / Whatever it is saying now / QNAP volume unmounted

Storage & Snapshots · Unmounted · Not active · Storage pool error · Check File System

QNAP says the volume is unmounted. Unmounted is a state, not a verdict, and Check File System is not the way out of it.

A QNAP volume shows Unmounted or Not active when QTS could not mount the file system at boot, or could not assemble the storage pool beneath it. The reasons run from a drive that dropped out of the RAID to a thin pool that filled up to an ext4 file system that a power cut left inconsistent to a firmware update that went wrong, and in every one of them the data on the drives is usually intact. The dashboard's remedy is Check File System, which runs e2fsck on the volume and writes what it decides is right, and on a volume sitting on a weak drive or a damaged pool it is how an unmounted volume becomes an unrecoverable one. Power down, label the bays, and send the set. A QNAP set is £500 + VAT upwards after the free look, fixed in writing, 5–10 days at the bench.

Free first lookOne fixed figure in writingNo data, no bill on most jobsReturn postage paid

Rather talk it through? An engineer answers the bench line
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Power it down. Label each drive with its bay number. Do not rebuild, repair, initialise, reinstall or reset. A rebuild reads every sector of every surviving drive, and on a set with a second weak member it finishes what the first failure began. Nothing on the drives gets worse while the unit is off.

What QTS stacks on the drives, and where each layer can stop.

QTS builds its storage in layers. Each drive carries a small system area and a large data partition; the data partitions are joined by mdadm into a RAID group; the RAID group is handed to LVM as a storage pool; inside the pool, a static, thick or thin volume is carved out; and the volume carries ext4. QuTS hero units replace most of that with ZFS. Unmounted is reported when the top of the stack, the file system, could not be mounted, and the cause can be anywhere beneath it.

A drive that dropped out of the RAID group leaves the pool degraded and usually still mountable; two leave it unassembled and the volume unmounted. A thin volume that was allowed to grow past the pool's real space stops the moment the pool fills, and every thin volume in that pool stops with it. A power cut in the middle of a write leaves ext4's journal and its metadata out of step, and QTS declines to mount it. A firmware update that failed can leave the boot flash unable to bring up the layers at all, with the pool untouched behind it.

Check File System addresses only the last of those, and addresses it by writing. e2fsck on a volume whose pool is missing a member repairs the wrong thing; on a thin volume with a damaged map it repairs the wrong blocks; on a drive with bad sectors it reads the weakest surface thousands of times. The bench images every drive first, assembles the RAID group and the pool from the images, rebuilds the thin-pool metadata where it needs it, and runs the file system repair on the virtual volume where nothing can be lost by trying.

What it says, and what it means.

Describe yours to us →
What you see The usual reason Where that leaves you
Volume: Unmounted; pool: ErrorRAID group missing membersEvery member imaged; assembled from the superblocks
Volume: Unmounted; pool: ReadyFile system inconsistentext4 repaired on the virtual volume
Thin volume unmounted; pool at 100 per centThin pool out of spaceThin metadata rebuilt from the images
Unmounted after a firmware updateBoot flash or QTS damaged; pool intactPool assembled from the images without QTS
Check File System ran and it is worsee2fsck wrote to a damaged volumeImaged; repaired on the image with what remains
QuTS hero: pool cannot be importedZFS metadata or too many members lostImported read-only from the images

From the box arriving to your files going back.

Work we have closed →
01

Logged the day it lands, and the first look costs nothing Free

A case number goes on the parcel and a number on every drive the day it is opened, and an engineer settles what has actually happened before anything spins. The unit is examined on its own; each drive is assessed on our own equipment, never in a NAS that will try to rebuild. Back to you come two things together: a straight note of what is liftable and what is not, plus one figure, fixed and written down. Accept it, or decline and owe us nothing.

Nothing to pay for lookingA single figure, put in writingNo rebuilds, no repairs, no resets
02

The unit, and the drives, apart

The box and the disks are two different jobs. The unit is tested separately, because a dead power supply, a failed board or a bricked boot flash leaves the drives untouched more often than not. Each drive is then read on the bench: the ones that answer at full speed, and the weak or failed ones in clean air where they need head work. On units that hold an encryption key or a layout of their own, the unit is part of the data and is kept with it.

Unit and disks assessed separatelyFailing members to the clean bench
03

Every member imaged, once

Nothing is worked on live and nothing is rebuilt on the originals. Every drive in the set is imaged sector by sector, the weak ones head by head with the bad areas last, and the SSD cache with them where there is one. From then on the originals are not touched again.

Every drive, including the cacheWeak areas last
04

The set put back together, from the images

Order, chunk size, parity rotation and the reshape point are read from the drives' own metadata and the array is reassembled in software: mdadm and LVM under SHR, X-RAID and QTS pools; a ZFS pool imported read-only; Drobo's BeyondRAID zones reconstructed. The file system, Btrfs, ext4, XFS or ZFS, is repaired on the virtual volume, and encrypted volumes are unlocked there with the key you supply. Never on the originals.

Rebuilt in software, from imagesThe file system repaired on the virtual volume
05

You see the file list before you pay

What was recovered is listed for you first, and only then does a bill exist. Approve the list and it is invoiced; turn it down and it is not — and where nothing has come back, most jobs carry no charge at all. Recovered data travels home on fresh media bought in for your job, with the postage at our end. Your case is not closed until you have opened the files on a machine of your own.

No charge until you accept the figureFresh media, supplied with the job5–10 days at the bench

From the bench

  • Do not run Check File System. It writes. On a volume over a degraded or damaged pool it repairs the wrong thing, and on a weak drive it reads the weakest surface thousands of times.
  • Do not update the firmware to fix it. An update rewrites the boot flash and, through QTS, can touch the pool's metadata. The pool is assembled from images without QTS at all.
  • A thin pool at 100 per cent is a stop-everything moment. Every further write lands in metadata the bench needs.
  • The data is on partition 3 of each drive. The boot flash and the system partitions carry QTS, not your files, and a bricked QNAP is a set of drives that read on the bench.

One job, followed all the way through.

UK · NDR-2026-0523JOB LOGGED ✓

A TS-453Be with the volume unmounted after a power cut, and a Check File System that had run for six hours before the owner stopped it

The pool was intact and the ext4 journal had been left inconsistent; the check had begun rewriting inode tables before it was stopped. All four drives were imaged, the RAID group and pool assembled from the images, and the ext4 file system repaired on the virtual volume from its backup superblocks and what the check had not yet touched. Everything but a handful of recently written files came back.

99.9% of it recovered5 days here, and back by post
Illustrative example — replace with a genuine case

What helps, and what harms.

Do this much first

  • Power it down
  • Write each bay number on its drive
  • Send every drive, the unit and its supply
  • Tell us the QTS version, the volume type and what was clicked

What sets us back

  • Running Check File System
  • Updating QTS to clear it
  • Removing or re-creating the pool
  • Moving the drives to another QNAP

Questions answered before you commit.

My QNAP says the volume is unmounted. Is the data gone?

Usually not. Unmounted means QTS could not mount the file system or assemble the pool; the drives usually hold everything. The pool is assembled from images and the file system repaired on the virtual volume.

Should I run Check File System?

No. It writes to the volume, and on a damaged pool or a weak drive it makes an unmounted volume an unrecoverable one. The bench runs the same repair on an image, where nothing can be lost.

My thin volume unmounted when the pool filled up. Is it corrupt?

Not usually; it is inaccessible until the thin-pool map is rebuilt, which is done from the images. Power down before anything else writes.

What does it cost?

A set is £500 + VAT upwards after the free look, fixed in writing; four bays or more from £1,250 + VAT.

How long does it take?

5–10 days at the bench.

Where this usually leads.

QNAP Deadbolt and Qlocker →Failed update or migration →iSCSI LUNs, VMs and Docker →QNAP →

Nothing gets worse while it is powered down.

Looking at it is free. Back comes a list of what opened and what did not, together with a single price to finish, set down in writing while you are still free to say no. Until that list reaches you, leave the unit off and the drives in their bays.

0800 6890668

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