[linux]rescan the hard drive after your vm got an expanded storage

The Tufin securechange vm got an expanded storage of 1TB more, however I cannot see it immediately with the fdisk -l command. I need to rescan it using echo "1" > /sys/class/block/sda/device/rescan, then do fdisk -l, you will see the /dev/sda with the full disk (after expanded). It works immediately..