From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 3 Nov 2002 12:01:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 3 Nov 2002 12:01:56 -0500 Received: from science.horizon.com ([192.35.100.1]:4671 "HELO science.horizon.com") by vger.kernel.org with SMTP id ; Sun, 3 Nov 2002 12:01:56 -0500 Date: 3 Nov 2002 17:08:23 -0000 Message-ID: <20021103170823.10591.qmail@science.horizon.com> From: linux@horizon.com To: linux-kernel@vger.kernel.org Subject: Re: [lkcd-general] Re: What's left over. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Just to complicate things, consider this setup: # cat /proc/swaps Filename Type Size Used Priority /dev/md5 partition 999864 16904 0 /dev/md6 partition 999864 16924 0 /dev/md7 partition 999864 16920 0 Those are all RAID-1 mirrors, a measure whose ass-saving value I have enjoyed. While a crash dump to just half of one of those mirrors is fine, finding it might be a little bit tricky. And the fact that the kernel reassembles the mirrors automatically on boot might make retrieving the data a little bit tricky, too. (After a crash, the mirrors will be inconsistent, so one will get copied over the other, but I'm not too clear on which direction it'll happen in.) I can't NOT reassemble at least some mirrors on boot because / is mirrored! Now, to that, add the case that each of those is significantly smaller than main memory. (2/3 size would still allow swap = 2*ram.) The problem is that hardware is getting more and more sopisticated and requiring ever more elaborate device drivers. Eventually you have to have a cutoff and say that something is too complex to talk to after a crash, even though it's theoretically available. Where is that line? USB? iSCSI? This situation? A reasonable fallback is to just drop in a cheap crappy dedicated IDE drive for catching crash dumps, but I'd like the crash dumper to know how to wake it up from sleep mode; I'd hate to leave it spinning all the time...