#!/bin/bash -e
# Test disk performance
# Adapted from https://www.shellhacks.com/disk-speed-test-read-write-hdd-ssd-perfomance-linux/
# Using bash because of redirects
test "$1" = "-w" && write=true && shift
disk="${1:-$(df --output=source . | tail -1)}"
if test "$write"
then exec &> >(tee ".disktest-$(date +%F)")
fi
highlight() { echo "$1"; }

highlight "Checking SMART with hdparm"
# Needs sudo for read test
sudo hdparm -MWAgt "$disk" || true

if test $# -eq 0
then highlight "Write Test"
	sync
	count=3000$(test $(df --output="avail" . | tail -1) -gt 999999 && echo 0 || true)
	tempfile=/var/tmp/.$count
	# Prevent deduplication/predictions by using random rather than zero, but since that is too slow we have to copy a previously created file
	test -s $tempfile ||
		( highlight "Preparing random bits:" &&
		sudo dd status=progress if=/dev/urandom of=$tempfile bs=1M count=$count ) &&
		highlight "Copying random bits:" &&
		sudo dd status=progress if=$tempfile of=.$count bs=1M count=$count
	highlight "Copying zero bits:" &&
		sudo dd status=progress if=/dev/zero of=.$count bs=1M count=$count
	sudo rm .$count
fi