How to share a physical disk directly over ISCSI

TrueNAS General
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1

Hi there. I would like to export a whole disk (/dev/sde) as an ISCSI extent, and I can’t figure out what I’m doing wrong.

I am running 25.04.2.4 and when adding an extent, I set the Extent Type to Device, but all I see in the device list are zvols, not disk devices.

The popup help for Extent Type lead me to belive this should work, it says " *Device* provides virtual storage access to zvols, zvol snapshots, or physical devices."

I have:

  • Verified that the disk I added is at /dev/sde – it appears in lsblk output and the Disks UI.
  • Tried wiping the disk to make sure it wasn’t detected as in use for something else.
  • Tried manually creating a partition table on the disk in case you’re supposed to export a single partition and not the whole device.
  • looked at the online documentation. It has a similar description that says physical devices can be be selected as extents.

I’m not sure what else to try. Can anyone spot what I am doing wrong?

Thanks,
KM

2

It’s unsupported on TrueNAS.

3

Well, that’s too bad, but thank you for getting back to me so quickly. It’s unfortunate that the documentation says the opposite and I wasted a bunch of time trying to figure it out.

Hopefully it’s possible to fix this confusion for the future. I’ve used the feedback button on the documentation page to report that it is incorrect.

Regards,
KM

4

Which documentation?

5

The “Extent Type” on this page includes “physical devices”:

The popup help in the UI to add extents says the same:

Screenshot 2025-09-15 170017
Screenshot 2025-09-15 1700171492×410 27.3 KB

And the AI documentation search came up with step by step instructions for it:

Screenshot 2025-09-15 164839
Screenshot 2025-09-15 1648391472×720 83 KB

Thanks,
KM

6

Okay. I told the docs team and they’ll fix it. IIRC we used to allow this with some old truenas versions and the docs were apparently never updated.

3 Likes
7

I remember this being brought up on the old forums, unfortunately I cannot link it here (it was thread ID 104740). It is supported on TrueNAS Core, but not on Scale. Scale removed this for some reason.

So this was solved by… the misleading term will be removed from the docs? Is there no way whatsoever to re-add this feature?
I found it to be extremely useful, since I don’t always require ZFS. By mapping an entire device into an extent, I can basically put existing drives into TrueNAS and have them appear with all data intact.

I would like it very much if this feature was re-added, or some work-around was created.

8

You can feel free to make a feature request thread.