I posted this in the snapraid forum but that doesn't seem to get much traffic.
So I tried to run a sync and it just fails with I/O errors that were limited to a single disk. So I removed the disk, put it in a dock on my desktop, added a new disk to the server and named it with the same disk label then copied all of the files from the removed disk to the server over NFS. I run MergerFS on this pool of disks so the rule is to fill the most empty disk first so it pretty much just copied everything from the removed disk to the new disk. I copied everything rather than running fix since the disk is still completely accessible a it's been a while since I synced, figured my safest bet was to just copy and resync. The files that it is complaining about haven't been touched in years, but I think if it had the chance it would error on every file of the disk. I've tested the RAM, moved the disk into a different SATA bay....same thing
There is pretty much 0 indication that there was anything wrong with the first disk. Running sync now with the new disk throws the same errors starting with the same files, so I moved the directory that was throwing the errors outside of the array and it's still throwing errors on the next files on this disk. I had no IO errors or anything while copying these files and there seems to be no actual problem with them. I think the parity for this disk is bad or something. I also did not copy the .content file to the new disk since I wasn't sure how that would be handled.
This was the first attempt at a sync since I moved 3 more partially filled disks into the array, hence there's a warning recommending 3 parity levels for 15 disks. These disks were already in the server, just outside of the Snapraid array......they are quite a bit smaller than the 6TB parity disks so I figured it wouldnt be an issue. What do I do to get sync running clean again?
Syncing...
Using 136 MiB of memory for 32 cached blocks.
Error reading file '/srv/dev-disk-by-label-PoolDisk7/YYY' at offset 1085014016 for size 262144. Input/output error.
Input/Output error in file '/srv/dev-disk-by-label-PoolDisk7/YYY' at position '4139'
DANGER! Unexpected input/output read error in a data disk, it isn't possible to sync.
Ensure that disk '/srv/dev-disk-by-label-PoolDisk7/' is sane and that file '' can be read.
Stopping at block 51245
Saving state to /srv/dev-disk-by-label-PoolDisk1/snapraid.content...
Saving state to /srv/dev-disk-by-label-PoolDisk2/snapraid.content...
Saving state to /srv/dev-disk-by-label-PoolDisk3/snapraid.content...
Saving state to /srv/dev-disk-by-label-PoolDisk4/snapraid.content...
Saving state to /srv/dev-disk-by-label-PoolDisk5/snapraid.content...
Saving state to /srv/dev-disk-by-label-PoolDisk6/snapraid.content...
Saving state to /srv/dev-disk-by-label-PoolDisk7/snapraid.content...
Saving state to /srv/dev-disk-by-label-PoolDisk8/snapraid.content...
Saving state to /srv/dev-disk-by-label-PoolDisk9/snapraid.content...
Saving state to /srv/dev-disk-by-label-PoolDisk10/snapraid.content...
Saving state to /srv/dev-disk-by-label-NasDisk1/snapraid.content...
Saving state to /srv/dev-disk-by-label-NasDisk2/snapraid.content...
Saving state to /srv/dev-disk-by-label-SSD1/snapraid.content...
Saving state to /srv/dev-disk-by-label-NVME2/snapraid.content...
Saving state to /srv/dev-disk-by-label-PoolDisk11/snapraid.content...
Verifying /srv/dev-disk-by-label-PoolDisk1/snapraid.content...
Verifying /srv/dev-disk-by-label-PoolDisk2/snapraid.content...
Verifying /srv/dev-disk-by-label-PoolDisk3/snapraid.content...
Verifying /srv/dev-disk-by-label-PoolDisk4/snapraid.content...
Verifying /srv/dev-disk-by-label-PoolDisk5/snapraid.content...
Verifying /srv/dev-disk-by-label-PoolDisk6/snapraid.content...
Verifying /srv/dev-disk-by-label-PoolDisk7/snapraid.content...
Error reopening the temporary content file '/srv/dev-disk-by-label-PoolDisk7/snapraid.content.tmp'. No such file or directory.