Date: Sun, 22 Sep 1996 03:20:27 -0400 From: "Gary Palmer" <gpalmer@freebsd.org> To: dwhite@resnet.uoregon.edu Cc: Brett Glass <brett@lariat.org>, questions@freebsd.org Subject: Re: systat/netstat utilities buggy? Message-ID: <6976.843376827@orion.webspan.net> In-Reply-To: Your message of "Sun, 22 Sep 1996 00:08:09 PDT." <Pine.BSI.3.94.960922000730.259O-100000@gdi.uoregon.edu>
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Doug White wrote in message ID <Pine.BSI.3.94.960922000730.259O-100000@gdi.uoregon.edu>: > On Sat, 21 Sep 1996, Brett Glass wrote: > > > Since I've begun to use them, the systat and netstat utilities appear > > to be causing trouble in my system. netstat often returns the message > > > > "kvm_read: Bad address" > > > > or hangs forever. systat -netstat sometimes also hangs forever (not > > always, but sometimes) and can cause odd system behavior -- as if memory > > were being corrupted. > > > > I've avoided these utilities to keep the machine from crashing, but really > > need to monitor the information they provide. > > > > Are there known problems with these programs? > > Not on my 2.1.5-R box. You may need to rebuild them and the kvm library, > especially if you are tracking -current. There is, actually. If the kernel's tables change while netstat (for example) is traversing it (because it gets stuck on a nameserver lookup somewhere), then it could get to a part of the table which doesn't exist anymore, and hence fall over with that error. It's quite common to see it on WWW servers, for example, where the network table changes very rapidly, and you typically have lots of connections from remote sites and hence nameserver lookups take a long time. Dunno about systat -netstat, never use it. As for `odd system behaviour', more details would be needed. Gary -- Gary Palmer FreeBSD Core Team Member FreeBSD: Turning PC's into workstations. See http://www.FreeBSD.ORG/ for info
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