OS Disk is /dev/sda.
Server has more than 27 disks.
So device name of last disk is /dev/sdaa.
Run disk-test.sh.
Command line used: /root/cluster-validation/pre-install/iozone -I -r 1M -s 4G -k 10 -+n -i 0 -i 1 -i 2 -f /dev/sdaa
Command line used: /root/cluster-validation/pre-install/iozone -I -r 1M -s 4G -k 10 -+n -i 0 -i 1 -i 2 -f a