I just installed two Seagate Ironwulf NAS harddisks of 4 TB in an Icy Box enclosure, Raid 1 set-up. I've setup a single partition using parted, and set up an ext4 filesystem. It's connected to a Raspberry Pi 4 running Raspberry Pi OS.
As soon as I mount the drive/partition, I hear the drive spin up as expected, and then a sound like a heartbeat can be heard - like the head is moving two times per second. I can share a recording if that would help.
This happens both when mounting manually via
sudo mount -t ext4 /dev/sdb1 /mnt/IcyBox and when automounting. This 'heartbeat' stops as soon as I unmount the drive. It seems I can successfully write to the drive - the heartbeat continues.
Now, since I'm just mounting the drive, and no programme supposedly is using it, is there a way to find out why the drive is spinning? And/Or would such a heartbeat sound be normal behaviour?