I have a question regarding mounting Unraid array disks outside of Unraid.

Setup:

• Unraid 7.1.4 Pro

• Several array disks: most are 512e, one disk is 4Kn

• Disk filesystem: XFS

• Debian 13 / Ubuntu 22.04 Live ISO tested

• Trying to mount the 4Kn disk:

  mount -t xfs -o nouuid,ro /dev/sdh1 /mnt/disk8

  or

  mount /dev/sdh1 /mnt/disk8

• Problem:

  • For all the four 512e disks, mounting works fine including rw

  • For the 4Kn disk, mounting fails with:

  mount: /mnt/disk8: mount(2) system call failed: Function not implemented （ubuntu）

  mount:/mnt/disk8:fsconfig()failed:Function not implemented.dmesg(1)may have more information after failed mount system call (debian)

• However, this disk works fine in the Unraid 7.1.4 array. I even tried rebuilding the array normally to clear and reformat this disk, but the problem persists. I just want to transfer some data in a Live CD environment because data transfer within Unraid consumes a lot of CPU.

• Question:

  • Is there any way to safely mount a 4Kn Unraid array disk on a Linux Live system for data recovery or inspection?

  • Or is it only possible to mount it within Unraid using the OS / Unassigned Devices plugin?

  • Any tips to safely access data without risking the array?

  Thank you for any advice or insights!

Edited November 4, 2025Nov 4 by xemaco

It's a known issue with 4Kn devices and XFS array devices, pool devices are fine, this should work:

mkdir /temp

mount -t xfs -o offset=0 /dev/sdX1 /temp

32 minutes ago, JorgeB said:

It's a known issue with 4Kn devices and XFS array devices, pool devices are fine, this should work:

mkdir /temp

mount -t xfs -o offset=0 /dev/sdX1 /temp

nice，than you very much!!