error 5, Unretryable

[Davvo]

I need minimum 4tb so not sure I would have enough space doing raid2.. More troubling is 2 enterprise black WD HDs failing within a few minutes of each other.. Its like winning the lottery

It's a fairly accepted fact that resilver heavily stresses your drives: since da1 was already on the brink of death it's reasonable that replacing the dead drive pushed it to its death. Also, with >2tb drives raidz1 is considered risky for this exact reason: consider buying an additional drive.
It is important to perform frequent (I do short every day and 1 long per week) smart tests on the drives in order to be aware if something isn't as it should be.
It is also very important (with some manufacturers more than others, but it's something not skippable anyway) to properly test and burn-in your drives (your system should be, but that's another thing) as soon as you get them to make sure they are ok.
When I get a new drive I make conveyance, short and long smart test in this order. Then I burn in.
There are plenty of resources on how on this forum, take a look.

 

[taylordude]

Okay, simpliest process for getting rid of any residual pool data still left? Scrub?

 

[taylordude]

never mind figured it out.

 

[taylordude]

Quick question. now my Truenas is not pulling active directory information. I would like to leave the domain and rejoin. How do you leave the domain so I can start the process over?

 

[taylordude]

To put a bow on this issue and close it out. I ended up defaulting the config, nuking the pools and starting over. I really appreciate the assistance from Davvo and Johnny, this forum continues to be true platform of support. That said it was recommended to me if you are going to deploy truenas I would have a backup System and that proved to be a valuable recommendation as it saved me hours getting it back online. I just wish there was more information about Raid and essentially how worthless Raidz and mirror are. You lose a drive and good luck getting back your data. I switched to 4 drives on a raidz2. The two drives I lost were WD Enterprise black drives and I have never lost two drives of that quality so quickly, so apparently raidz really takes its toll very quickly. Thanks again for the assistance, some very smart folks on here.

 

[Davvo]

The following resources can help deepen your understanding of zfs (and TrueNAS).

Introduction to ZFS

This is a short introduction to ZFS. It is really only intended to convey the bare minimum knowledge needed to start diving into ZFS and is in no way meant to cut Michael W. Lucas' and Allan Jude's book income. It is a bit of a spiritual...

www.truenas.com

Hardware Recommendations Guide

This is the latest edition of the FreeNAS Community hardware recommendations guide. The current major version is R2, dated January 2021, with the last minor update on 2021-01-24. The format has moved away from the forum post form factor, to...

www.truenas.com

https://www.ixsystems.com/wp-content/uploads/2022/02/ZFS_Storage_Pool_Layout_White_Paper_February_2022.pdf

When you have time, take a look in the forum (resource section is a good place to start). There is much knowledge to be discovered.

 

[Whattteva]

I just wish there was more information about Raid and essentially how worthless Raidz and mirror are. You lose a drive and good luck getting back your data. I switched to 4 drives on a raidz2.

The forums like to frown on RAIDZ1 and in most cases, it's warranted, but I wouldn't go as far as saying it's worthless depending on your risk tolerance. I have backups and relatively small drives in RAIDZ1 that I've been running for the last 10 years with zero issues. I've replaced 1 drive that was failing and started throwing errors on SMART tests. But I foresee myself still maintaining this setup for at least another 5 years. I think as long as you monitor your drives, RAIDZ1 is totally fine on smaller drives (i.e. 1-3 TB or less). Of course, no matter what RAIDZ you're running (even RAIDZ3), it is NEVER a replacement for actual backups. RAID is just simply a method to mitigate downtime.

For two enterprise level drives to fail simultaneously.... while it's possible, sounds extremely unlikely. Have you been running long SMART tests at all? You can catch dying drives early with that.