headers: device %busy avque r+w/s blks/s avwait avserv
headers: device %busy avque r+w/s Kbs/s avwait avserv
Reports activity for each block device
Reports buffer activity
Reports system calls
Reports use of file access system routines
Reports tty device activity per second
Reports message and semaphore activities
Reports kernel process activity
Data not graphed
Reports status of process, i-node, file tables