Re: Raid5 Read stats for parity cal...

On Wednesday September 16, linuxraid.study@gmail.com wrote:

Hello:

I understand that parity calculations are not done as part of Raid5
read operation in normal running conditions.

Correct.

However, it would be done during disk failure or when a sector is bad.

Also correct.

Is there a way (any stats) available to see if parity cal are done
when sector is bad (since this is not as obvious as a disk fail...)

Maybe you want
   /sys/block/mdX/md/dev-YYY/errors

which counts the number of sectors for which md found a read error and
had to generate correct data using parity, and then wrote that correct
data back.

NeilBrown