0-byte files - ReadyNAS Pro 6

I have a strange issue & have found some simimlar threads, but nothing seems to match the exact symptoms that I'm experincing, so I thought I'd start a new topic.

I have several ReadyNAS units, including an old ReadyNAS Pro 6 that was unofficially upgraded to OS6.  This unit is currently being utilized as a "backup NAS" .  6-WD10 Red Pro drives in a RAID-5 config,

A few months back, I began noticing some 0-byte files - but didn't think much of it, because I figured it may be caused by an rsync error.

Looking into it further, I discovered that when files are being written to the (either directly or via RSYNC) NAS, they have a file size.  Performing another RSYNC job will cause many of the smaller files to all of a sudden appear as 0-bytes.  Running RSYNC again will put the file sizes back - only to have the same patterns repeated.  This only appears to be an issue with smaller files.

I then decided to run an RSYNC, check a folder with command ls -lS (lists files by descending file size) - there are no 0-byte files.  Rebooted NAS, then performed command ls -lS - several 0-byte files.

I figured it might be a write-cache issue, so I disabled write-cache on the drives utilizing hdparm -W0 /dev/sda thru /dev/sdf.  Issue persisted.

After I upgraded the NAS from 4.x, I upgraded the memory from the 1GB chip to 2x2GB (4GB total), using memory that others have had success with.  I figured that perhaps the issue is bad RAM - so I ordered another 2x2GB using a different memory brand that others have suggested, and the problem still persists.

Right around the time I first started noticing the problem, I had a disk go bad & when I pulled it out, the problem persisted.  I also started experiencing random lock-ups & could not get the system to boot.  Replacing the power supply fixed this issue.  But the 0-byte issue still exists.

Because the problem existed on the original PS as well as the new one, I don't think it is a power-related issue.  The drive status in the GUI (as well as using smartctl --all /dev/sda thru /dev/sdf) all appear to be fine.

I tried creating a small file utilizing dd if=/dev/urandom of=Test.flie bs=7K count=2

I then performed md5sum Test.flie & got a result.  Rebooted NAS.

When NAS rebooted, I went back into SSH & executed md5sum Test.flie - different result.  And performing ls -l, Test.file exists as 0-bytes.

I don't have an issue rebuilding the NAS if it will resolve the issue - but before I do so, I'm hoping that someone can offer me some guidance as to how to proceed.  I'm assuming that a log file will potentially contain clues, but I'm unsure exactly what to look for.

Running 6.10.3 - have tried upgrading to 6.10.6, but problem still exists (and then downgraded back to 6.10.3).

Thank you

-Dan