Well, today is turning out to be a bit of a pain with disk drives (esp with zero sleep last night).
I have an external ICY BOX JBOD box with one Seagate Barracuda and one Samsung Momentus drive in it and both drives being accessed about every second or so going by the activity lights.
Neither drive is the boot drive - the Pi B+ (v1.2) is booting from an SD card with an up to date Buster Light on it.
No applications are running on the Pi and the disk is not being accessed by anything else on the LAN.
The only things I can see is the task 'usb-storage' coming up to the top of TOP.
Bus 001 Device 004: ID 067b:2773 Prolific Technology, Inc. PL2773 SATAII bridge controller
lsusb -t gives:
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dwc_otg/1p, 480M |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/5p, 480M |__ Port 1: Dev 3, If 0, Class=Vendor Specific Class, Driver=smsc95xx, 480M |__ Port 5: Dev 4, If 0, Class=Mass Storage, Driver=usb-storage, 480M
top shows usb-storage nearly always at the highest CPU when nothing else is running on the system.
fstab line for this drive is
LABEL=FileArchive /mnt/FileArchive ext4 nofail,defaults,noatime 0 1
I've tried killing the process to double check it is this but to no avail - it does not want to die.
Checking before and after the drive is attached
dmesg | grep usb-storage
[ 2.592298] usbcore: registered new interface driver usb-storage
[ 2.592298] usbcore: registered new interface driver usb-storage [ 222.734216] usb-storage 1-1.5:1.0: USB Mass Storage device detected [ 222.741069] scsi host0: usb-storage 1-1.5:1.0
but as soon as I issue the mount command (either manually or via
sudo mount -a, the access starts again.
sudo e2fsck -vf /dev/sda1 but that came up clean.
Trying the Samsung drive in another USB hub does not show the activity flash and I've tried adding usb-storage.quirks=067b:2773u to the start of cmdline.txt (yes I know the USB ports are only USB 2 on the Pi - I'll try anything at the moment) but that did not help.