I have an odd issue, and i'm trying to figure out if it could be drives going bad, or something working in the background that chooses to use this specific drive. I have one RAID1 set which shows constant activity with associated drive noise, but my other two RAID1 sets are quiet. This is in a T420 with the H710 PERC controller. 

Originally when i first built this server, I had a RAID 10 and the noise was there, so i thought maybe there was something wrong so i halved and made it RAID1 to see what would happen, same issue. SO i'm wondering if one or some of the drives i'm using in this array are showing signs of doom. All drives are the exact same, 8TB HGST 7.2K SAS, throughout the server.

I did read about another user having a similar issue here: https://www.dell.com/community/PowerEdge-HDD-SCSI-RAID/Hard-DRive-Light-Constant-Activity/m-p/1988157#M12009, however the FTP site that was linked i could not get to. This "Patrol Read Utility" that is mentioned, is this still a thing 16 years later? What else could be the issue? At this point, i might just take the drives out and try another set, but before i do that, i want to ask the group. Thanks!