From owner-freebsd-stable Tue May 26 07:15:20 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id HAA00636 for freebsd-stable-outgoing; Tue, 26 May 1998 07:15:20 -0700 (PDT) (envelope-from owner-freebsd-stable@FreeBSD.ORG) Received: from whizzo.transsys.com (whizzo.TransSys.COM [144.202.42.10]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id HAA00609 for ; Tue, 26 May 1998 07:15:10 -0700 (PDT) (envelope-from louie@whizzo.transsys.com) Received: from whizzo.transsys.com (localhost.transsys.com [127.0.0.1]) by whizzo.transsys.com (8.8.8/8.7.3) with ESMTP id JAA10716; Tue, 26 May 1998 09:12:29 -0400 (EDT) Message-Id: <199805261312.JAA10716@whizzo.transsys.com> X-Mailer: exmh version 2.0.1 12/23/97 To: Robert Watson cc: Dag-Erling Coidan =?iso-8859-1?Q?Sm=F8rgrav?= , stable@FreeBSD.ORG From: "Louis A. Mamakos" Subject: Re: vnconfig + swap with sparse files References: In-reply-to: Your message of "Mon, 25 May 1998 17:15:57 EDT." Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Date: Tue, 26 May 1998 09:12:29 -0400 Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by hub.freebsd.org id HAA00614 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk > Indeed, I did not expect the pager to swap to my sparse file -- I expected > the file to become un-sparse as it went along. Even if you *could* make this work, would you want to? From my experience years ago using a NeXTSTEP computer with a Mach OS which generally *only* used a swapfile, you want to preallocate the file. This gives the filesystem the opportunity to make better (and perhaps continguous or within the same CG) block allocation. In fact, the installation procedure allocated the swapfile very early on in the software installation process before the disk space became fragmented. On the NeXT, they used a dedicated program rather than dd as suggested before, mostly because they didn't have a /dev/zero I think. That being said, the NeXTSTEP OS did dynamically grow the swapfile as required, and when the system was booted, it truncated the file at some pre-configured size. The "holy grail" that everyone wanted was the ability of the OS to contract a swapfile it had grown beyond it's initial (preallocated) size, but as far as I know, this never happened. louie To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message