From owner-freebsd-hackers Wed Feb 17 5:26:39 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from ns1.yes.no (ns1.yes.no [195.204.136.10]) by hub.freebsd.org (Postfix) with ESMTP id 2A0AA10E88 for ; Wed, 17 Feb 1999 05:26:31 -0800 (PST) (envelope-from eivind@bitbox.follo.net) Received: from bitbox.follo.net (bitbox.follo.net [195.204.143.218]) by ns1.yes.no (8.9.1a/8.9.1) with ESMTP id OAA12574; Wed, 17 Feb 1999 14:26:30 +0100 (CET) Received: (from eivind@localhost) by bitbox.follo.net (8.8.8/8.8.6) id OAA70173; Wed, 17 Feb 1999 14:26:29 +0100 (MET) Date: Wed, 17 Feb 1999 14:26:28 +0100 From: Eivind Eklund To: Brandon Gillespie Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: savecore before swapon? Message-ID: <19990217142628.F69668@bitbox.follo.net> References: <19990216082600.A15274@ice.cold.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.1i In-Reply-To: <19990216082600.A15274@ice.cold.org>; from Brandon Gillespie on Tue, Feb 16, 1999 at 08:26:00AM -0700 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, Feb 16, 1999 at 08:26:00AM -0700, Brandon Gillespie wrote: > I havn't checked the source, but from my understanding shouldn't > savecore be run before swapon is run, incase the swap device is the > dump device? Or to look at it another way, when swapon is run on a > swap device, does it look first to see if there is a dump in it, and > if so what does it do? Right now we run swapon, then considerably > later we run savecore. Assuming swapon just trashes whatever was in > that device, running savecore is pretty much irrelevant, as most > people I know (not necessarily in FreeBSD) use their swap device as a > dump point. This is done intentionally, as fsck may in some cases require swap to be able to fsck large filesystems. It would make sense to have a sysctl 'only_swap_as_absolutely_last_resort_not_for_performance' AKA 'do_linux_swapping_scheme' which was set before the swapon, and unset after the crashdump. I don't know how to implement this. (It might be that one of the present sysctls does something like this - I've not checked). Eivind. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message