z2 pool of 6 drives is resilvering suddenly, 4 drives are degraded? Help to undestand please!

[Angrily4845]

I am in a bit of a (maybe) pickle and would appreciate some help, thoughts and just understanding what is happening.

So I have just shutdown my server and started it back, without any hardware changes.
The below is what is happening currently:

I do not understand concretely what is happening and about 40 mins of searching nets nothing close to what I am experiencing.
How are 4 drives suddenly degraded and 2 are resilvering if I read correctly?

Is anyone able to say with a degree of certainty if my pool will actually recover?
I checked SMART data on all these drives and it seems fine, there is another 2 drives in a striped pool off the same controller running just fine.

I am very confused at my current situation, would greatly appreciate if someone can help walk me through any troubleshooting or just explain what I have missed.

Your help and time is appreciated. Thanks!

 

[Angrily4845]

Well I am at a loss, this happened, it seems its all ok now?!?

It stopped on its own like this:

I did the zpool clear at the end and now it looks like this, much better

I am actually not satisfied because I do not know what has actually happened to cause this. I have been having a rock stable time on TrueNAS for years, even doing drive replacements without issue.

Any help on identifying what gives, even tho the issue appears to be resolved?
Thanks!

 

[somethingweird]

Wouldn't it be nice if we got hardware specs?

 

[Angrily4845]

It could, but skipped my mind while trying to figure out what was going on

Hardware:
- Dell T630 chassis thats been modded to accept ATX and EATX motherboards
- The T630 HDD backplane modded to work with any motherboard/SAS controller
- Gigabyte MZ32-AR0 v1.0 motherboard
- AMD Epyc 7532 CPU
- 8x 32GB 2400MT Registered ECC memory
- Micron 9300 Max 3.84TB U.2 drive (VM storage as LVM thin currently while modding the last/3rd of these, otherwise CEPH is running on it for VM storage)
- Crucial MP510 960GB M.2 drive (unused this second)
- Dual Samsung 845DC PRO 400GB in a ZFS mirror running Proxmox as boot drives
- Mellanox CX3 dual 40GB NIC
- LSI SAS 9300-8i flashed with stock firmware in IT mode connected to the T630 backplane
- 5x Toshiba Enterprise 16TB HDD and 1x Toshiba Enterprise 20TB HDD in the above mentioned Z2 pool "big"
- 2x WD White 8TB HDD in a stripe in the same TrueNAS VM/same controller in pool "small"

Software:
- Proxmox 7.4 as base
- VM running TrueNAS CORE 13.0-U5.2 (assigned 8 CPU cores, 64GB memory with balooning off, q35 machine type and all VirtIO drivers for performance)
- The TrueNAS VM has the LSI SAS 9300-8i card passed through correctly to the VM

Thanks!