trurl

Latest beta is kernel 5.7

Have you ever used one of the Unraid 6.9 betas?

Nothing apparent in those. 2 FAQs that might be relevant:

The main thing I was hoping for more clarity on was your question. Did you replace disk8 with a different disk to begin rebuild? Or were you rebuilding to the same disk? What exactly do you mean by "just put it back in the system"?

Maybe diagnostics would help clarify and possibly show other considerations. Go to Tools - Diagnostics and attach the complete Diagnostics ZIP file to your NEXT post in this thread.

Syslog snippets are seldom sufficient. Go to Tools - Diagnostics and attach the complete Diagnostics ZIP file to your NEXT post.

Do you have the Unassigned mapped with slave access?

Prefer is the correct setting and Yes is most definitely the wrong setting. Probably After you get Cache fixed post new diagnostics and we can work on that.

Maybe diagnostics would answer some questions and let us see if anything else needs to be considered.

If the disk is actually disabled then Unraid isn't using it until rebuilt anyway. And I don't think I would bother trying to rebuild it to itself. Of course, while disabled, any access to that disk will be emulated by reading all other disks. And unless you have dual parity you don't have redundancy either. Do any of your other disks have SMART warnings on the Dashboard?

Go to Tools-Diagnostics and attach the complete Diagnostics ZIP file to your NEXT post in this thread.

Have you done memtest?

/boot

Rebuild will start over from beginning.

Also

Probably unrelated, but why do you have 200G allocated to docker.img? Have you had problems filling it? 20G should be more than enough and if it grows you likely have some application writing to a path that isn't mapped. Making docker.img large will not fix that problem, it will just make it take longer to fill.

johnnie.black addressed the main thing, but some other things to consider. You shouldn't run for long on batteries. The point of having batteries is so you can cleanly shutdown, not so you can keep running. Is your UPS compatible with the APCUPSd builtin to Unraid? Why do you have 50G allocated to docker.img? Have you had problems filling it? 20G should be more than enough, but I see you are already using 18G. I suspect you have some application misconfigured and it is writing to a path that isn't mapped. Also, your system share has files on disk1 instead of all on cache. Possibly this happened when you recreated docker.img while still having cache problems, or maybe you enabled dockers / VMs before you installed cache. Your dockers/VMs will keep those files open, so array disks can't spin down, and they will have their performance impacted by slower parity.

Excluding disks I assume?

Also, that driver is already included. Are you sure you don't have some actual hardware problem (cable, port, switch) with your network connection?

Do you have any spare ports? Try to use your intel ports and not the Marvell ports.

There isn't any way to install drivers in the GUI or otherwise. What version of Unraid are you using?

Go to Tools-diagnostics and attach the complete Diagnostics zip file to your NEXT post

USB connections are not reliable enough for the permanent connections required in the array or pool.

Pairing HDD with SSD sort of defeats the purpose of having SSD since it will only work at HDD speed. And if redundancy is what you had in mind you apparently didn't accomplish it as shown by johnnie.black. I assumed you were just combining capacity so no redundancy since that is what your screenshot showed. You also need to consider getting those ReiserFS disks converted.