home *** CD-ROM | disk | FTP | other *** search
- Path: sparky!uunet!zaphod.mps.ohio-state.edu!cs.utexas.edu!sun-barr!west.West.Sun.COM!news2me.EBay.Sun.COM!exodus.Eng.Sun.COM!appserv.Eng.Sun.COM!appserv!limes
- From: limes@ouroborous.eng.sun.com (Greg Limes)
- Newsgroups: comp.sys.sun.admin
- Subject: Re: iostat -D util - what is it
- Date: 23 Nov 92 12:38:54
- Organization: Sun Microsystems Computer Corporation
- Lines: 19
- Distribution: na
- Message-ID: <LIMES.92Nov23123854@ouroborous.eng.sun.com>
- References: <BxvLoo.AuK@ccu.umanitoba.ca>
- NNTP-Posting-Host: ouroborous
- In-reply-to: pam@ccu.umanitoba.ca's message of Tue, 17 Nov 1992 19:48:24 GMT
-
- In article <BxvLoo.AuK@ccu.umanitoba.ca> pam@ccu.umanitoba.ca (Pat Macdonald) writes:
- | For SunOS (4.1.2) the man page for iostat states the following:
- |
- | > -D For each disk, report the reads per second, writes per
- | > second, and percentage disk utilization.
- |
- | Can somebody please tell me what "percentage disk utilization" is?
-
- Every 100th of a second, the system looks at each of the [first 32] disks
- in the system to see if a command is pending; if there is one, then a
- corresponding counter is incremented.
-
- The iostat command watches these counters, and divides the number of
- counts added to them by elapsed time, giving a percentage of the time
- ticks when the disk was observed to have a pending command. 100% means
- that every clock tick saw the disk was busy.
-
- Note that 100% doesn't necessarily mean you can't get more transactions
- through the disk, it just means that the disk is always doing something.
-