From owner-freebsd-questions Tue Oct 1 16:18:28 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 7E3DA37B401 for ; Tue, 1 Oct 2002 16:18:26 -0700 (PDT) Received: from cactus.fi.uba.ar (cactus.fi.uba.ar [157.92.49.108]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7496343E65 for ; Tue, 1 Oct 2002 16:18:25 -0700 (PDT) (envelope-from fgleiser@cactus.fi.uba.ar) Received: from cactus.fi.uba.ar (cactus.fi.uba.ar [157.92.49.108]) by cactus.fi.uba.ar (8.12.3/8.12.3) with ESMTP id g91NFmHo072734; Tue, 1 Oct 2002 20:15:48 -0300 (ART) (envelope-from fgleiser@cactus.fi.uba.ar) Date: Tue, 1 Oct 2002 20:15:47 -0300 (ART) From: Fernando Gleiser To: "Weston M. Price" Cc: freebsd-questions@freebsd.org Subject: Re: Character Devices vs. Block Devices In-Reply-To: <200210011612.08538.wmprice@direcway.com> Message-ID: <20021001201058.D81915-100000@cactus.fi.uba.ar> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Spam-Status: No, hits=-3.4 required=5.0 tests=IN_REP_TO version=2.31 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 On Tue, 1 Oct 2002, Weston M. Price wrote: > So, given this, I am assuming that hard drives are treated as raw devices > exclusively? That is, no intermediate buffers are maintained between the user > process and the device: Nope, there is buffering for the file system interface. I dont remember the exact reasons for nuking the block devices, but I think it has to do with the new VM subsystem and the integrated buffer cache/VM, but my memory may be failing. If you want a more acurate answer, search the archives for -hackers and -current > > Is this valid on FreeBSD? Nope. The book was written before FreeBSD nuked block devices. Fer > > Regard, > > Weston > > On Tuesday 01 October 2002 03:19 pm, Weston M. Price wrote: > > Hello, > > A quick ls of my dev directory revealed that each one of my hard drives 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 on > > 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 > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message