From owner-freebsd-questions Tue Oct 1 13:20:40 2002 Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 66A4F37B401 for ; Tue, 1 Oct 2002 13:20:38 -0700 (PDT) Received: from hughes-fe01.direcway.com (hughes-fe01.direcway.com [66.82.20.91]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8945D43E3B for ; Tue, 1 Oct 2002 13:20:37 -0700 (PDT) (envelope-from wmprice@direcway.com) Received: from jerusalem ([66.82.48.1]) by hughes-fe01.direcway.com (InterMail vK.4.04.00.00 201-232-137 license dcc4e84cb8fc01ca8f8654c982ec8526) with ESMTP id <20021001202057.UXEO1393.hughes-fe01@jerusalem> for ; Tue, 1 Oct 2002 16:20:57 -0400 Content-Type: text/plain; charset="iso-8859-1" From: "Weston M. Price" To: freebsd-questions@freebsd.org Subject: Re: Character Devices vs. Block Devices Date: Tue, 1 Oct 2002 16:12:08 +0000 User-Agent: KMail/1.4.3 References: <200210011519.59430.wmprice@direcway.com> In-Reply-To: <200210011519.59430.wmprice@direcway.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Message-Id: <200210011612.08538.wmprice@direcway.com> Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG So, given this, I am assuming that hard drives are treated as raw devices= =20 exclusively? That is, no intermediate buffers are maintained between the = user=20 process and the device: =46rom The Design and Implementation of the 4.4 BSD operating system: "The character interface does not copy the user data into a kernel buffer= =20 before putting then on an I/O queue. Rather, it arranges to have the I/O = done=20 directly to or from the address space of the process. " Is this valid on FreeBSD?=20 Regard, Weston On Tuesday 01 October 2002 03:19 pm, Weston M. Price wrote: > Hello, > =09A quick ls of my dev directory revealed that each one of my hard dri= ves is > considered a character device by the system. Example: > > crw-r----- 2 root operator 116, 0x00010002 Aug 19 16:09 /dev/ad0 > crw-r----- 2 root operator 116, 0 Aug 19 16:09 /dev/ad0a > crw-r----- 2 root operator 116, 1 Aug 19 16:09 /dev/ad0b > crw-r----- 2 root operator 116, 2 Aug 19 16:09 /dev/ad0c > crw-r----- 2 root operator 116, 3 Aug 19 16:09 /dev/ad0d > crw-r----- 2 root operator 116, 4 Aug 19 16:09 /dev/ad0e > crw-r----- 2 root operator 116, 5 Aug 19 16:09 /dev/ad0f > crw-r----- 2 root operator 116, 6 Aug 19 16:09 /dev/ad0g > crw-r----- 2 root operator 116, 7 Aug 19 16:09 /dev/ad0h > > What I am confused about, aren't hard drives treated as block devices o= n > most systems? What am I missing? > > Regards, > > Weston > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-questions" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message