I have Intel RST RAID 1 running on a Windows 7 machine. I have it set to do a verify and repair every week. I frequently notice parity errors, some weeks over 100 for a 1 TB RAID 1 array. I've never had a media error, however.
I suspect that a drive is going bad since I didn't see this when the drives were new, but I can't figure out the cause. I've looked through Event Viewer, and opened the RST application. I see nothing amiss. Should I try running a 3rd party SMART utility?
The drives are consumer drives, but I assume that it's not a TLER issue since this is Intel RST, not a high-performance hardware RAID. Also, if a drive timeout is the cause, I would expect the array to become degraded, and I've not seen that. Nor are there any events in the Event Viewer.
I'm also curious as to how RST knows how to repair a parity error for RAID 1. Does it arbitrarily pick one of the copies as the good copy, or does it maintain a logical timestamp for each block and so knows which copy is more up-to-date.
UPDATE: I've used smartmontools to check the SMART status. Both drives report back as healthy.
