Unable to import a pool after power outage PLEASE HELP

[Arwen]

Welcome to the TrueNAS forums!

I can’t answer the question of how to help. Seems you’ve done a lot to attempt recovery.

Perhaps someone else will have a suggestion.

However, if I am reading the ZDB output correctly, both your disks in “pool2” are wired via USB:

                phys_path: 'pci-0000:00:14.0-usb-0:1:1.0-scsi-0:0:0:0'
                phys_path: 'pci-0000:00:14.0-usb-0:2:1.0-scsi-0:0:0:0'

This is likely the root cause of the metadata corruption:

Why you should avoid USB attached drives for data pool disks

This subject has been coming up quite often since about 2022. Perhaps because of TrueNAS SCALE has brought forth some attention to TrueNAS in general and ZFS in specific. Please note that this is about USB attached storage for ZFS data pools. On occasion, people use USB drives, (flash, USB->SATA, USB->NVMe, etc…), for booting. In general, these do work acceptably, (when not using the cheapest USB flash drives). Though, it is always recommended to backup your configuration in case of boot drive …

Many times USB attached disks seem to work, except when they don’t. Especially like during a power fail.

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Here is something I wrote up on ZFS and power fails:

ZFS pools & power loss - you won't lose data

There is sometimes misconceptions about ZFS losing data due to power loss. The subject of power loss, (or OS crash), and then not being able to import a ZFS pool comes up here in the forums a few times a month. Here is the skinny on what should happen. There are several things to un-pack about power loss affecting ZFS and data loss. Any previously stored data in a ZFS pool can not be / is not lost on power loss. Exception is in hardware failures that affect pool redundancy. Like the loss of b…