Fangtooth Instances ISO upload issue

Apps and Virtualization
1

I just upgraded to Fangtooth and I’m trying to create Instances. However anytime I upload an ISO via the GUI it constantly stops at 80-90% with the wolloding error:

Error (0)

Http failure response for https://***: 0 Unknown Error

When I check for the file via:
zfs list -t volume
I get a partially uploaded file. Is there a way I can either fix the upload via the GUI or transfer the ISO another route?

2

We’re adding a UI option to select a path on the TrueNAS server’s data pool for ISO source.

2 Likes
3

Do you know what version this will be implemented, and how to mount an ISO in the meantime?

4

I found the issue: Instances | TrueNAS Documentation Hub

Image Filename Requirements
Valid instance names must meet the following conditions:

  • The name must be between 1 and 63 characters long.
  • The name must contain only letters, numbers and dashes from the ASCII table.
  • The name must not start with a digit or a dash.
  • The name must not end with a dash.
5

My issue was different but I was able to fix it. Since it was uploading to high 80% mark I figured it might be a timeout of sorts and if so i needed a few more seconds of upload time within the timeout. Turned off wifi and connect straight to my router and was able to successfully upload to 100%. Seems like there’s some sort of timeout thats set pretty low for ISO uploads.

2 Likes
6

I want to raise serious concerns regarding the current state of TrueNAS, particularly its ability to support virtual machines—a core advertised feature.

When I upgraded to TrueNAS Community Edition 25.04.00, I did so with full awareness that issues might arise. As a technically capable user, I expected to encounter bugs and was prepared to implement workarounds where necessary. That’s part of working with a newer platform. However, the problems I’ve encountered go far beyond typical beta instability—they reflect a lack of basic functionality in one of the two primary use cases for TrueNAS: virtualization and storage.

Most critically, the inability to reliably upload Windows installation ISOs—which often exceed 5GB—makes the system unfit for standard VM provisioning tasks. The platform only allows ISO uploads through a single mechanism in the web UI. That upload process routinely fails with timeouts and offers no alternative path for uploading large files (e.g., via SSH, dataset mounting, or external storage), no meaningful logs, and no documentation on where the UI stores uploaded files. Without the ability to attach ISO files or even access where they’re stored, the process dead-ends.

For example:

  • On one server, I was able to upload a Windows installer ISO without issue after having issues trying to migrate VM after update.

  • My other Windows Server VM, on an identical system which I was able to migrated after the update, began randomly shutting down and corrupting system and configuration files.

  • I’ve been trying to upload the same ISO on this system going on four days without success.

  • Attempts to locate the upload file location via SSH or find have failed, due to hidden file structure and undocumented paths preventing me from uploading the ISO through alternative methods.

  • After backing up a known-good configuration, I planned to spin up a fresh VM—an operation that should be simple and routine. Instead, I’ve spent several days unable to even get to the point of attaching an ISO.

I understood the risks of adopting this version early, and I’ve already worked through known challenges. But a platform meant for reliable storage and virtualization must support its fundamental use cases out of the box—or at the very least, provide documented workarounds when problems arise.

Now, I’m beyond the point of rolling back to the previous version of TrueNAS, and I’m left with a system that can no longer fulfill one of its core functions.

I strongly urge the development team to address this with urgency:

  • Provide alternative methods for ISO upload (SSH path, dataset use, or removable storage).
  • Improve the reliability and speed of the existing ISO upload mechanism.
  • Offer visibility into where uploaded ISOs are stored or cached.
  • Document current limitations clearly, along with workarounds where available.
  • All of which should have been addressed prior to releasing the update as these are known issues with the new VM management system they adopted/modified for their use.

Until these issues are resolved, TrueNAS Community Edition 25.04.00 cannot be considered a viable platform for running Windows virtual machines. These are not edge cases—they are core functionality failures that affect a wide range of users.

7

I had a similar issue with an ISO from the GUI (maybe a timeout?)
Anyway, had success loading it via the command line:
$ sudo incus storage volume import Alice /mnt/Alice/Miscellaneous/Software/xyz.iso xyz.iso --type=iso

  • Alice is the name of the pool
  • /mnt/Alice/Miscellaneous/ is the location of the source iso file
  • xyz.iso is the name of the file

This loads directly from the filesystem into the incus store.

1 Like
8

I was getting a different error also (413), and your solution worked for me as well.