htop can do all (most?) of what iotop can. Press S in htop and you can select to show i/o-related data, including number of bytes and number of operations in t

htop can do all (most?) of what iotop can. Press S in htop and you can select to show i/o-related data, including number of bytes and number of operations in total and per second. You will need to be root to look at most i/o related data.