My server is having major issues with constant UDMA CRC read errors. Now my parity drive and disk 2 are said to be bad. The array will not boot. I ran an extended Smart test on disk 2 and its said that its fine. Now I am at a loss as I need this server to either boot with disk 2 so I can replace the parity drive or with the parity drive so i can rebuild the array. Also was wondering if my SAS card could be causing all these errors and if I should replace it. Is there any way to get unraid to ignore the udma errors and just boot? I am kind of a noob with unraid. I posted my diagnostic files here. 

ares-diagnostics-20231130-2359.zip

Start by updating the LSI firmware to latest since that's very old, if that doesn't help replace the SATA cables.

3 hours ago, jonny_blaze said:

My server is having major issues with constant UDMA CRC read errors.

 

CRC errors indicate connection errors.  Since CRC error counts are stored internally to the drive they never reset to 0 so you can only stop them increasing.   You can ask Unraid to only tell you about changes by clicking on the Orange icon for the drive on the Dashboard and selecting the Acknowledge option. 

 

In the vast majority of cases it is the power or SATA cabling to the drive causing the CRC errors to occur, although as was mentioned old LSI firmware seems to sometimes cause this to happen when it should not.   A quick way to check the cabling is to swap it with another drive and see if the errors follow the drive or the cabling.

well I changed out the SAS card and cables and now my parity drive and disk 2 will not be recognized by Unraid. Do I have to change out the drives and lose the data that was on disk 2? Or do I need to start fresh and clear out all the drives? I am relatively lucky as I do have a back up server that has most of but not all the data lost. Could there be other issues with the MB or something else I am not thinking of? Your help would be most appreciated. Thank you.

Attach new Diagnostics to your NEXT post in this thread.

ok here are my diagnostics. I thought of a work around. I was able to mount the disk with unassigned devices, share the drive and pull the data off the drive to a usb hdd. But this just tells me the drive is probably still good and that if I replace it with a new drive and a new parity drive, whos to say this wont continue to happen?

ares-diagnostics-20231220-2056.zip

I assume this was disk2?

 

Device Model:     WDC WD100EMAZ-00WJTA0
Serial Number:    1EG1N5GZ

 

If yes it looks healthy, you can do a new config, assign it and re-sync parity.

Well I am kind of a noob ….how do I do that?

5 hours ago, jonny_blaze said:

Well I am kind of a noob ….how do I do that?

Tools->New Config.

 

That tool is mentioned here in the online documentation accessible via the Manual link at the bottom of the Unraid GUI.  In addition every forum page has a DOCS link at the top and a Documentation link at the bottom.   The Unraid OS->Manual section covers most aspects of the current Unraid release.

Just a follow up, I was able to do a reconfig and add the drive back into the array. I was also able to do a parity sync and everything seems back to normal now. I guess the issue was either with the old SAS card or its cables. I replaced both with newer versions. Thanks to everyone who helped me figure this out.