I have the exact same issue as described in this thread.
Raspberry Pi 2 powered by a good 2A 5V power supply with only a network cable attached to it ... and the PiDrive.
Powering the Pi and PiDrive separately did not make a difference.
There is no info/error related to USB/PiDrive in
But I have found a 'workaround' to make the beep go away:
Starting the bitcoind daemon which causes EXTENSIVE writes to the PiDrive, which makes me think that it has to do with some sleep/power saving state. When the daemon isn't running and I hear the beeps, there is always write activity, hence my suspicion.
Here's the systemd unit file for bitcoind I have created:
# cat /etc/systemd/system/bitcoind.service
Description=Bitcoin's distributed currency daemon
ExecStart=/usr/bin/nice -n 19 /usr/bin/bitcoind -datadir=/srv/cryptocurr/bitcoin/
ExecStop=/usr/bin/bitcoin-cli -datadir=/srv/cryptocurr/bitcoin/ stop
But I'd rather not use this 'workaround' as it causes a rather high load on my system and way more writes to the PiDrive then needed.
If you want/like, I can provide advanced details about my system as I am quite proficient in Debian and thus Raspbian.
I'm one of the maintainers of the Raspbian NetInstaller with which this system was initially setup, but it is now mostly switched to (pure) Debian Testing, with
bitcoind taken from Debian Sid (as it isn't available anywhere else).
The root of the filesystem is on the SD Card (Samsung EVO 32GB) and I have divided the PiDrive into 3 Logical Volumes (LVM) which are mounted separately:
# cat /etc/fstab
/dev/mmcblk0p1 /boot vfat defaults 0 0
/dev/mmcblk0p2 / f2fs noatime 0 0
tmpfs /tmp tmpfs defaults,nodev,nosuid 0 0
#UUID=1ef8cd13-e569-4587-9750-bf1c3519207b /var ext4 defaults 0 2
/dev/vgPiDrive1/lvVarPart /var ext4 defaults 0 2
/dev/vgPiDrive1/lvCryptoCurr /srv/cryptocurr ext4 defaults 0 2
/dev/vgPiDrive1/lvNfsShare /srv/nfs/share ext4 defaults 0 2