bin/136759: iostat(8) displays wrong I/O statistics with -c 1

[Efstratios Karatzas]

The following reply was made to PR bin/136759; it has been noted by GNATS.

From: Efstratios Karatzas <gpf.kira at gmail.com>
To: bug-followup at freebsd.org, vovets at gmail.com
Cc:  
Subject: Re: bin/136759: iostat(8) displays wrong I/O statistics with -c 1
Date: Wed, 13 Jan 2010 16:40:48 +0200

 Hi there,
 
 This is definitely not a bug. Take a look at the freebsd man page for iostat(8)
 
 http://www.freebsd.org/cgi/man.cgi?query=iostat&apropos=0&sektion=8&manpath=FreeBSD+8.0-RELEASE&format=html
 
 The manual clearly states that :
 "The first statistics that are printed are averaged over
  the system uptime.  To get information about the current activity, a
  suitable wait time should be specified, so that the subsequent sets of
  printed statistics will be averaged over that time."
 
 So the first line of statistics always contains the "average
 statistics" since the system started running.
 If you want to get the statistics for the next 5 secs try something
 like iostat -c 6 -d some_device
 
 Hope this helps
 
 -- 
 
 Efstratios "GPF" Karatzas