From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4225C43441 for ; Mon, 19 Nov 2018 23:47:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 786D72080C for ; Mon, 19 Nov 2018 23:47:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=thunk.org header.i=@thunk.org header.b="QxRpRLyr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 786D72080C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=mit.edu Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732144AbeKTKNI (ORCPT ); Tue, 20 Nov 2018 05:13:08 -0500 Received: from imap.thunk.org ([74.207.234.97]:54380 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727583AbeKTKNH (ORCPT ); Tue, 20 Nov 2018 05:13:07 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=thunk.org; s=ef5046eb; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=Ael0izyb6injiRpOvRaspckUDWtdFagaQgon+O+fIsY=; b=QxRpRLyr6k4Nrvi/UN3ZCl17bk p+O69pWrZYmDNOBybjUC1j/VbDo5/c58Yi/eMxHGYQxwbTLrVxVEdaoMPzzq7z8megEIOxW8/tBTa 5NSZVrcyK3KmuZKQ+tm8LRYD+UVRoRSAH4yVxQx805pEAP/I0UtEUs41l6Yt+sVgUeyI=; Received: from root (helo=callcc.thunk.org) by imap.thunk.org with local-esmtp (Exim 4.89) (envelope-from ) id 1gOtFn-0002eN-Fp; Mon, 19 Nov 2018 23:46:55 +0000 Received: by callcc.thunk.org (Postfix, from userid 15806) id 7F5EE7A046D; Mon, 19 Nov 2018 18:46:54 -0500 (EST) Date: Mon, 19 Nov 2018 18:46:54 -0500 From: "Theodore Y. Ts'o" To: Randy Dunlap Cc: AIAMUZZ , linux-kernel@vger.kernel.org Subject: Re: Magic Sysrq key option ... What is the option to record the boot logs to my hard disk before i issue a reboot command ? Message-ID: <20181119234654.GD17374@thunk.org> Mail-Followup-To: "Theodore Y. Ts'o" , Randy Dunlap , AIAMUZZ , linux-kernel@vger.kernel.org References: <20181119184803.GB19377@thunk.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on imap.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 19, 2018 at 11:31:21AM -0800, Randy Dunlap wrote: > > Yes, all of that. > Having some kind of pstore on x86 would be wonderful. > > kexec/kdump used to be an option also. I haven't tried it lately. Sure, but kexec/kdump won't work to debug a boot failure during early boot. You need to be able to get the root file system mounted at the very least, and usually kexec/kdump doesn't get set up until the init scripts are running. Fortunately, usually only kernel developers need to debug early boot failures, and most of us can usually use serial consoles (for those of us who can't just cheat and use VM's. :-) - Ted