I noticed a few days ago that when transferring several ISO files from my Windows machine to the ISO folder on Unraid, the Unraid GUI stopped responding. I was still able to ping the server and SSH into it, so I rebooted and didn’t think much of it—figured it might’ve been a WiFi hiccup during the transfer.

Today, I connected via Ethernet (using a dock in my office) and tried again. The same thing happened—the GUI froze. After testing, I found that small files copy fine, but transferring large files (a few GB or more) causes the system to freeze.

After troubleshooting, I narrowed it down to files being added to the ISO folder, which lives on my ZFS cache pool. Running zpool status -v gave me this error:

Interestingly, the referenced Home Assistant directory doesn’t even exist in the ISO folder. I tried removing it via the terminal, but the server froze again. I even tried deleting the entire ISO folder, but the same thing happened.

A while back, I noticed that deleting folders via ZFS Master usually doesn’t remove the folder, but it never froze the system like this. I believe I only converted the appdata folder into a ZFS dataset. I’m not sure if that matters, since the ISO folder is still within the same ZFS pool.

My question is:
How can I fix this issue? I’m fairly new to ZFS and not sure how to safely repair or restore the pool. The only two folders I need to preserve are:

• appdata

• emby metadata (which I don't think was converted to a dataset)

Any help is appreciated—thank you!

unraid-diagnostics-20250706-1547.zip

Scrub the pool and see if anything changes.