# Writes
nohup dd if=/dev/zero of=/disk1/file.bin bs=5G count=1 oflag=direct </dev/null > disk1.out &
nohup dd if=/dev/zero of=/disk2/file.bin bs=5G count=1 oflag=direct </dev/null > disk2.out &

#Reads
sync ; echo 3 > /proc/sys/vm/drop_caches

nohup dd if=/disk1/file.bin of=/dev/null bs=8k </dev/null > disk1_read.out &
nohup dd if=/disk2/file.bin of=/dev/null bs=8k </dev/null > disk2_read.out &