TrueNAS server won't reboot and returns "zio_error 5" and "ZFS i/o error" instead

TrueNAS General
1

Hi. I was watching videos from my TrueNAS and a few days ago I saw an error on the screen connected to the NAS itself. I rebooted but got the same error:

zio_read error: 5
zio_read error: 5
zio_read error: 5
ZFS: i/o error - all block copies available

It repeats that on the screen and then ends with:

ERROR: error loading module ‘password’ from file ‘/boot/lua/password/lua’:
/boot/lua/password.lua:1: unexpected symbol.

I use half the NAS to store videos and last watched a video some three weeks ago. TrueNAS interface was working fine in September 2025.

Please let me know what the above error means and point to how I can correct this.

Thanks!

2

You likely lost your boot device. If you have a saved copy of your configuration, then it is a simple mater to install a new boot device and re-install the same version of TrueNAS. Then restore the configuration.

What is your hardware configuration?
Like what are you using for your boot device?