Hello to all.  I am a long-time user of unraid in a very simple config (just using it as a file server, no dockers, vms etc which are too technical for me).  Before transferring files (which I do in a non-automated way using either Teracopy or Windows explorer) from my Windows PC to Unraid I create checksums for each file and occasionally check these on the unraid shares.  I recently noticed that checksum verification shows errors on all files I have transferred recently.  Files I transferred on 16/06 are god but files transferred on 30/09 and since are corrupted it seems.  I am running v6.7.2 but I cannot say if the problem is related to the version as I do not know when I updated.  I have tried using Teracopy to do the transfers, with the verify setting ticked, and it also fails the verification test.

Would be very grateful for any possible assistance.   

unraid-schr-diagnostics-20191110-1947.zip

My immediate suspicion would be RAM related issues.    I would suggest running a memory check for something like 24 hours

Thank you itimpi.  Following your suggestion I ran memtest for 22 hours and 22 passes but no errors found.

Unfortunately with memtest only a positive result confirms there are issues, a negative one it's never for certain, hence why ECC RAM is commended for anyone who cares about data integrity.

 

I believe RAM is still the most likely culprit, but it could also be for example a controller issue, try to copy to disks using different controllers, if corruption happens with all it's likely a RAM issue (or possibly CPU/board)

Are the files that are having an issue all on the same disk? If so, which one?

I'm also a bit curious if you've tried comparing with a hex editor or something to see what is being changed.

I have since (following suggestions  here - tks johnnie & snicky) copied files to different disks, using different controllers, and all copies were corrupt. I then hooked up another unraid box and found that it too had the same issues.  Moving the system from my basement to  the study (still connecting to same LAN) cured the issue: so now I must assume that the problem is in a segment of my LAN .. . . :-(