bonienl, thanks for taking the time to help. Here are some details and additional observations (i.e. incomplete filenames/paths in the logs, and pausing during copy). I'm guessing your #1, #3, and #4 recommendations don't apply in my situation.
1. Unraid 6.6.5 running on Dell PowerEdge T110 II, Intel® Xeon® CPU E3-1240 @ 3.30GHz, 16GB ECC, 2x4TB WD Red, 2TB WD, 1TB Hitachi, 128GB SSD (Unassigned). CyberPower CP1000PFCLCD UPS. Wired network.
2. Unraid array filesystem is encrypted XFS using passphrase
3. Memtest86 passed. SMART and Parity tests pass.
4. Windows 10 Desktop PC (NTFS) containing family photos/videos to be backed up. JPG and MOV files.
5. Created a Public SMB Share (/photos) that only includes one empty disk of the array. (keeping it simple for testing purposes). Copy-on-write on Auto. Cache disk disabled. Enhanced OS X interoperability disabled.
6. Plugins installed: Unassigned Devices, Community Applications, Dynamix File Integrity,
7. Docker and VM enabled but none installed.
8. Dynamix File Integrity options: Auto protect new files=Enabled. Hashing method=BLAKE2 (also tried SHA2). Save hash to flash=Disabled. Excluded folders/files=docker.img,libvirt.img and Apple metadata. Verification schedule=Daily.
1. On Windows PC, I navigate to //towerl/photos and then drag/copy a directory of photos (inside are subdirectories of photos separated by date/event) from the local drive to the Unraid share. There are ~40,000 files totalling 160GB. This takes a few hours.
2. Wait for the daily hash verification check and the parity check (I set this to be more frequent for testing purposes)
SHA256 hash key mismatch, is corrupted
SHA256 hash key mismatch, /Jimmy Samsung/20160518_215300.jpg is corrupted
SHA256 hash key mismatch, bbean cruise/00013.MTS is corrupted
SHA256 hash key mismatch, ion/IMG_0408.JPG is corrupted
SHA256 hash key mismatch, ion/IMG_0815.JPG is corrupted
SHA256 hash key mismatch, thering at Janice/DSC_8135.JPG is corrupted
SHA256 hash key mismatch, up shots/DSC_7719.JPG is corrupted
1. Firstly, not sure if it's related but while copying I notice that the transfer speed is 40+MB/s but drops to 0MB/s for several seconds every few minutes or so. During those times when it's dropped to 0MB/s I notice that one to two CPU cores is at 100% in the Unraid dashboard.
2. Daily hash verification shows ?? files hash mismatch. (see log excerpt above). These are for JPG and MTS (Video) files that don't change.
3. Note that in the first entry the filename is empty and for the other files, the filepaths are incomplete.
4. Subsequent hash verifications show identical errors and log output.
5. I've compared file hashes using other tools and also bitwise compare (cmp) to confirm that these so-called corrupted files are indeed identical to the source files.
6. Parity check shows 0 errors.
I repeated the above. That is, I deleted the files and copied the same directory again. This time a different set of files show errors and subsequent hash verifications consistently show errors on that new set of files.
As another test, I used mc on Unraid to make a copy of the folder locally on the array (i.e. taking Windows out of the loop). Similar result, the new copy had another set of files that show errors consistently. Again, file compares showed that the files were bitwise identical.
I then changed the hash method from SHA2 to BLAKE2 and did a manual Build in the Integrity menu to recalculate the hashes for all files. The next daily hash verification showed no errors. However, after copying more files from the Windows PC, a few hash errors were found again in the new files.
Any other things for me to try? Thanks.