I have another disk notification appeared today...

The machine which is listing this (HP Proliant ML310e v2) has a disk enclosure so I dont think this can be a cable/connection issue.

Do I need to worry about this error?

I haven't been able to reboot it yet, to see if it clears!

I have attached diags... any thoughts appreciated.

Thanks in advance

unraid-diagnostics-20251109-1616.zip

Clear the error by clicking on the fail icon on the Main Tab.

Monitor, if you get more errors, post details and diagnostics.

Most CRC errors are the result of data corruption in the transfer from the hard disk to the HBA interface. Basically, we are talking about the SATA data cable and the SATA connectors. And the error is always corrected by resending the data. It does slow down the data transfer rate but unless you are having hundreds of errors per hour, you would never realize that. It will keep popping up a notice which is much more annoying than any other effect of it. I believe the notification can be suppressed in the ARRAY section of the Dashboard. But the notification will reactivate should the count increases again.

21 hours ago, ConnerVT said:

Clear the error by clicking on the fail icon on the Main Tab.

Monitor, if you get more errors, post details and diagnostics.

Thanks.... although I dont actually see a "fail" tab - is it somewhere else;

14 minutes ago, SliMat said:

Thanks.... although I dont actually see a "fail" tab - is it somewhere else;

Oops - My bad. I meant the OTHER main tab. The one my server initally loads, called DASHBOARD. 😄

Sorry about that.

12 minutes ago, ConnerVT said:

Oops - My bad. I meant the OTHER main tab. The one my server initally loads, called DASHBOARD. 😄

Sorry about that.

Ah, thanks - found it...

OK... today I received another error... now showing that UDMA CRC Error Count is 2...

So, I will remove the RAID enclosure and check all the connections are clean and well seated... but cant do this till the weekend.

Or would the general recommendation be to just replace the SSD?

So, is there any plugins which will backup my cache disk in case it fails, so I can recover my apps/VMs etc?

Thanks

Edited November 17, 2025Nov 17 by SliMat

2 hours ago, SliMat said:

Or would the general recommendation be to just replace the SSD?

Absolutely NOT!!!! This is almost always a problem with data corruption during the transmission of of the data from the disk to the HBA (99.99% of the time). Loose connections and SATA data cables are usually the cause. Most of the time the problem is fixed by cable replacement.

This problem can be occasionally caused by cross-talk between SATA cables if they are tightly bundled together--usually done for neatness by OCD people.

2 hours ago, SliMat said:

So, I will remove the RAID enclosure and check all the connections are clean and well seated... but cant do this till the weekend.

For me, this is NOT a panic situation and would be a last resort only if I was getting hundreds of errors a week. There are two or three threads each month on the forum by people with problems that were caused by working inside of their cases and accidentally loosening a SATA connector. (The design of the SATA connector system is the post child on how not to design a connector!!!) IF you do dive into the case, double and triple check every SATA connector when you are done before you restart the system. I use single drive HD enclosures (often called hot-swap) and I have had an occasional problem with a one or two. I just replaced them. (I currently have three disks disks with more than more than 100 CRC errors--- one with more than 1800 ---and I am not taking any action at this time. It has been months since the last one. It is not a panic situation.)

2 hours ago, SliMat said:

So, is there any plugins which will backup my cache disk in case it fails, so I can recover my apps/VMs etc?

Look at the appdata backup plugin. But I don't believe it does VM's...

IF you are considering buying a new SATA drive, have a look at creating cache-pool with redundancy.

42 minutes ago, Frank1940 said:

The design of the SATA connector system is the post child on how not to design a connector!!!

Truer words never written.

And the 12 volt high power Nvidia connector