[Linux] Device/File system test script

#!/bin/ash

i=1
while true; do
        FILENAME=/mnt/hd/test.tmp
        BLOCKSIZE=1M
        BLOCKCOUNT=100

        echo "--- Write ($i) ---"
        dd if=/dev/zero of=$FILENAME bs=$BLOCKSIZE count=$BLOCKCOUNT conv=sync

        echo 3 > /proc/sys/vm/drop_caches
        echo 0 > /proc/sys/vm/drop_caches

        echo "--- Read ($i) ---"
        dd if=$FILENAME of=/dev/zero bs=$BLOCKSIZE count=$BLOCKCOUNT

        rm -f $FILENAME
        i=$(($i+1))
done