Hi there. Unraid newbee here. Half year fighting with "udma crc error count" problem. Always same scenario: Disabled disk, than after reboot not even found (Disk 5 Not installed). After shutdown and some hw operations (swapping sata cables) appeared in unassigned devices.

 

 

First I thought I am facing disk problem, so I bought another one. The problem came again. So I started to check forum. I changed all SATA cables. Problem did not disappear. Than I changed PSU. Still not any change. I swapped SATA cables (problem disk with another one), nothing changed. I swapped power supply cables (problematic one used 4pin adapter). Still same disk, same crc error problem. No idea how to deal with it   ....any help is appreciated. Attaching diagnostic file. THX so much in advance. Still love unraid

tower-diagnostics-20230109-1923.zip

By itself it should not cause CRC errors but change the controller from IDE to AHCI, it will at the very least increase performance and can possibly help with the dropped disks issues.

Thx for your answer. Where do I have do this? Bios? No idea where this setting is. Just tried to google it and looks like it is some setting in bios.

Yes, board BIOS. 

I bought a 10 Sata PCI-e 4x card and it gave me these errors on every channel. Its a communications failure somewhere , maybe that SATA port has gone bad.

Guys...my bad! I started from scratch and found I have made mistake when marking disks. So my "Disk 5" wasn't one I thought and I was dealing with wrong one. So...finally...I changed SATA cable on right one and for now it looks like solved problem. Thx for your help and really sorry for my mistake.
@braydin72 I just ordered PCI-e 2xSATA card....want to add 2nd parity and (may be) cache disk. So will see how this will works.