From owner-freebsd-hackers Sat Jul 6 16:42:34 2002 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 61D2737B400 for ; Sat, 6 Jul 2002 16:42:32 -0700 (PDT) Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2]) by mx1.FreeBSD.org (Postfix) with ESMTP id EAF3C43E09 for ; Sat, 6 Jul 2002 16:42:31 -0700 (PDT) (envelope-from dillon@apollo.backplane.com) Received: from apollo.backplane.com (localhost [127.0.0.1]) by apollo.backplane.com (8.12.5/8.12.4) with ESMTP id g66NgNLA063860; Sat, 6 Jul 2002 16:42:23 -0700 (PDT) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.12.5/8.12.4/Submit) id g66NgMri063859; Sat, 6 Jul 2002 16:42:22 -0700 (PDT) (envelope-from dillon) Date: Sat, 6 Jul 2002 16:42:22 -0700 (PDT) From: Matthew Dillon Message-Id: <200207062342.g66NgMri063859@apollo.backplane.com> To: Bernd Walter Cc: Terry Lambert , Darren Pilgrim , ticso@cicely.de, freebsd-hackers@FreeBSD.ORG Subject: Re: How does swap work address spacewise? References: <20020705113532.GA11273@atrbg11.informatik.tu-muenchen.de> <20020705133515.GA295@HAL9000.wox.org> <20020705133837.GA513@HAL9000.wox.org> <20020705234126.GA12183@atrbg11.informatik.tu-muenchen.de> <3D2640A7.3EA2236B@pantherdragon.org> <20020706020656.GL48977@cicely5.cicely.de> <3D2762FE.9D9E0378@pantherdragon.org> <20020706220720.GG23704@cicely5.cicely.de> <3D277274.B5F3CE58@pantherdragon.org> <3D2776BE.A39A1110@mindspring.com> <20020706231346.GJ23704@cicely5.cicely.de> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Negative block numbers are used by UFS to represent the indirect blocks associated with a file, while positive block numbers represent the contents of the file. These are logical block numbers, which are fragment-sized (1K typically). So, 2^31 x 1K = 2TB. Physical block numbers are 512-byte sized, with a range of 2^32 in -stable. This also winds up being 2TB. So increasing the fragment size does not help in -stable. In -current physical block numbers are now 64 bits, removing the 2TB limit, and UFS2 uses 64 bit block numbers, removing the filesystem-imposed 2TB limit. I'm not sure how much more work there is to go in this area, you could ask Poul or Kirk. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message