RAID 5 Rebuild in Progress but Volume Showing Unmounted – QNAP TVS-1271U-RP

English Storage
1

Hi everyone,

I need some advice regarding an issue with my QNAP NAS.

NAS model: QNAP TVS-1271U-RP
QTS version: 4.2.1

Storage configuration:

8 × 4TB disks

RAID 5

What happened:

One of the disks (Bay 2) failed. The NAS was still accessible and the data was available because it was running in degraded RAID-5 mode.

To replace the failed disk, I did the following:

  1. Shut down the NAS

  2. Removed the failed disk from Bay 2

  3. Inserted a new 4TB disk of the same size

  4. Powered the NAS back on

After booting:

  • The new disk status shows “rebuilding”

  • The RAID group status is also “rebuilding”

  • However, the volume is showing as “unmounted” in storage manager

Currently the rebuild process is running.

My questions:

  1. Is it normal for the volume to appear unmounted during RAID rebuild on this QTS version?

  2. Will the volume automatically mount once the rebuild is finished?

  3. Is there anything I should avoid doing while the rebuild is in progress?

The data is important, so for now I am just letting the rebuild continue without making any changes.

Any advice or similar experiences would be very helpful.

Thanks.

2

First of all, you should not shut down when replacing a disk. It’s meant to be hot swapped. I am not sure what can/may happen when things are done in your situation.

You say your data is important. I hope you have a backup.

A RAID is not a backup

You may want to open a support ticket with QNAP.

1 Like
3

Yeah, shutting the NAS down wasn’t clever.

During a normal hotswap rebuild, the data would be available, even though with reduced performance

4

Hi,

Rebuild is completed.

Still volume is unmounted.

Is there anyway to mount manually.

Thanks

5

You can always try to reboot the NAS..

But i would also recommed to contact QNAP support.

6

Currently file system check in progress.
20% completed.
also created ticket to qnap.

7

To help us track the progress of your case more efficiently, could you please provide your support ticket number?

Thanks!

8

Hello Everyone,

Thank you for your time and efforts in trying to help with this issue.

After running the file system check for approximately 24 hours, the volume mounted automatically and I am now able to access all the data without any issues.

Currently, the storage pool is completely full, so I am planning to expand the capacity by adding two more disks to the existing RAID group.

I will be following the steps mentioned in the QNAP documentation below for expanding the storage pool by adding disks to the RAID group:

https://docs.qnap.com/operating-system/qts/5.0.x/en-us/expanding-a-storage-pool-by-adding-disks-to-a-raid-group-FD20DB.html (https://docs.qnap.com/operating-system/qts/5.0.x/en-us/expanding-a-storage-pool-by-adding-disks-to-a-raid-group-FD20DB.html)

Please let me know if there are any additional recommendations or precautions I should take before proceeding.

@SteveKo ticket number is Q-202603-15646. The support engineer asked me for debug log from helpdesk app but I already start running file system check, due to file system check I am unable to provide log, the engineer also mention that wait for the file system check.

Thank you again for your assistance.