Shingled drives are NOT suitable for RAID. NAS drives are marketed as designed for NAS, and thus for RAID. WD has started to ship some shingled drives with NAS labels. They didn't admit it for almost a year. <https://blocksandfiles.com/2020/04/14/wd-red-nas-drives-shingled-magnetic-recording/> <https://nascompares.com/2020/04/16/your-wd-red-nas-hard-drives-might-be-using-smr-what-you-need-to-know/> Shingling is a useful technique for increasing disk density. But it has performance implications. They are horrible for RAID. In fact they can cause RAIDs to fail. I'm currently not affected but if I were I'd search for a class-action suit to join.