iostat(8) says: -w Pause wait seconds between each display. If no wait interval is specified, the default is 1 second. iostat itself disagrees: iostat -xw iostat: option requires an argument -- w usage: iostat [-CdhIKoTxz?] [-c count] [-M core] [-n devs] [-N system] [-t type,if,pass] [-w wait] [drives] Suggest dropping the second sentence from the man page entry.
From r215786: Clarify a few details about iostat(8) behavior: - The default repeat count for iostat(8) is 1 unless there was a -w on the command line. The second sentence should remain, but perhaps could change to "If -w is not specified, [...]".
No not really as if -w isn't specified it doesn't do interval based display.
(In reply to Steven Hartland from comment #2) > No not really as if -w isn't specified it doesn't do interval based display. Not even if a -c count is specified?
You're correct if -c X is specified by no -w then it defaults to 1 second.
Bug 153012 is similar, and has a patch that might be useful.
The cleanups I made for vmstat.8 in r269727 might also be worth looking at.