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Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!ihnp4!ucbvax!kupfer
From: kupfer@ucbvax.ARPA (Mike Kupfer)
Newsgroups: net.unix-wizards,net.bugs.4bsd
Subject: Re: Missing feature in config(8)
Message-ID: <7940@ucbvax.ARPA>
Date: Fri, 7-Jun-85 22:21:06 EDT
Article-I.D.: ucbvax.7940
Posted: Fri Jun  7 22:21:06 1985
Date-Received: Sat, 8-Jun-85 05:43:58 EDT
References: <1653@psuvax1.UUCP>
Reply-To: kupfer@ucbvax.UUCP (Mike Kupfer)
Distribution: net
Organization: University of California at Berkeley
Lines: 25
Keywords: disk, instrumentation
Xref: watmath net.unix-wizards:13452 net.bugs.4bsd:1548

In article <1653@psuvax1.UUCP> templin@psuvax1.UUCP (Fred L. Templin) writes:
>	Now, at boot time, when the autoconf.c routine "configure" probes
>each nexus for devices, it picks out the first "DK_NDRIVE" (DK_NDRIVE = 4)
>entries in the mbdinit structure which have the "mi_dk" flag set and assigns
>them "dk" entries.  
> ...
>This messes up the utilities "vmstat" and
>"iostat", since they use the "dk" entries to display information for the
>disks, and "configure" chose the wrong ones!

A more general problem is that if your system really uses more than 4
disks, you can only monitor 4 of them with any one kernel.  Also,
iostat and vmstat know in 4.2 that there are only 4 instrumented disks.

The iostat and vmstat that will come with 4.3 let you specify arbitrary
disks (up to 4 for any invocation of the program, for formatting
reasons).  Alas, DK_NDRIVE is still stuck at 4, so 4.3 will still have
the "4 instrumented disks per kernel" limit.  Ideally, of course, the
kernel should instrument every disk that makes it through
auto-configuration.  Maybe next time...
-- 
Mike Kupfer
kupfer@ucb-arpa or kupfer@Berkeley
...!ucbvax!kupfer
``You can tell the pioneers by the arrows in their backs.''