From owner-freebsd-hackers@FreeBSD.ORG Sun Feb 1 12:29:37 2004 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B944616A4CE for ; Sun, 1 Feb 2004 12:29:37 -0800 (PST) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by mx1.FreeBSD.org (Postfix) with ESMTP id 532F143D3F for ; Sun, 1 Feb 2004 12:29:36 -0800 (PST) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.12.10/8.12.10) id i11KTXUG033440; Sun, 1 Feb 2004 14:29:33 -0600 (CST) (envelope-from dan) Date: Sun, 1 Feb 2004 14:29:32 -0600 From: Dan Nelson To: Joe Schmoe Message-ID: <20040201202932.GA25030@dan.emsphone.com> References: <20040201020256.17498.qmail@web21501.mail.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040201020256.17498.qmail@web21501.mail.yahoo.com> X-OS: FreeBSD 5.2-CURRENT X-message-flag: Outlook Error User-Agent: Mutt/1.5.5.1i cc: freebsd-hackers@freebsd.org Subject: Re: What kind of a crash is this ? (kernel ? userland ?) X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 01 Feb 2004 20:29:37 -0000 In the last episode (Jan 31), Joe Schmoe said: > I have become familiar with certain FreeBSD crashes - namely, I can > tell the difference between the kernel crashing, and the userland > crashing. > > If the machine is down, but I can still ping it, then the userland > has crashed - the kernel is still running, which is why it responds > to pings. "userland" doesn't crash (except maybe if you break libc.so). Rather, one binary most likely is not running. You may be able to telnet in if ssh is not running, for example. > But if it crashes and just reboots itself, then the kernel has > crashed. Oversimplified I know, but I am leading up to: > > What kind of a crash is it if: > > I can ssh to the system, it gives me the BSD copyright and the uname > message, but never ever gives me a prompt. What is going on in this > scenario ? What kind of things have you seen that cause a crash like > this ? Hit ^T and find out what command on the remote side is currently running, and what it's waiting on. Could be DNS, a remote NFS server not responding, local disk problems, etc. -- Dan Nelson dnelson@allantgroup.com