WARNING: mismatch_cnt is not 0

I got an email regarding this issue saying something like :

 

WARNING: mismatch_cnt is not 0 on /dev/md1

The /dev/mdX can vary depending on how many raid partitions you have. This mismatch_cnt value is the value of the blocks,

that are not synchronized between RAID-1 (mirrored) drives.  On my server it looked something like :

To fix :

And after the repair is completed:

Then check to see what this returns: