From owner-freebsd-newbies Thu Jul 25 17: 5:30 2002 Delivered-To: freebsd-newbies@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id EBA3037B412 for ; Thu, 25 Jul 2002 17:05:25 -0700 (PDT) Received: from spork.pantherdragon.org (spork.pantherdragon.org [206.29.168.146]) by mx1.FreeBSD.org (Postfix) with ESMTP id 50A7843E72 for ; Thu, 25 Jul 2002 17:05:25 -0700 (PDT) (envelope-from dmp@pantherdragon.org) Received: from sparx.pantherdragon.org (evrtwa1-ar10-4-61-236-062.evrtwa1.dsl-verizon.net [4.61.236.62]) by spork.pantherdragon.org (Postfix) with ESMTP id EFF6E471DC; Thu, 25 Jul 2002 17:04:20 -0700 (PDT) Received: from pantherdragon.org (speck.techno.pagans [172.21.42.2]) by sparx.pantherdragon.org (Postfix) with ESMTP id 54CFCFDA0; Thu, 25 Jul 2002 17:04:18 -0700 (PDT) Message-ID: <3D409202.B9355D0F@pantherdragon.org> Date: Thu, 25 Jul 2002 17:04:18 -0700 From: Darren Pilgrim X-Mailer: Mozilla 4.76 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Marco Berizzi Cc: hiten@uk.FreeBSD.org, freebsd-newbies@FreeBSD.ORG Subject: Re: block device vs char device References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-newbies@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Marco Berizzi wrote: > > thanks for the patience. > I have read the man pages you have pointed me > before writing to the list but they don't > explain clearly the difference (at least for me). > Idem the handbook. Sometimes it reports you should > use cd0c (possibly) and some examples (take a look > at the SAP installation section) reports cd0a. > > Currently for me it is not clear why should I use > cd0c and not cd0a to mount a cdrom (or viceversa). > Both device are working well for me (this make me angry!!!). > I would like to know which is the difference between the > two nodes (the minors are different). cd0a and cd0c are different representations of the disc. Reading up on disklabel will give you some clues about this. The "a" and "c" are partition numbers, though "c" has special meaning. cd0a refers to the first ISO filesystem on the CD. cd0c refers to the entire disc. You should use cd0a for mounting a disc. There are also the audio-track device nodes: cd0t{1-100). These aren't created by default (MAKEDEV all). You can create them seperately by saying, `MAKEDEV cd0t`. > >From: Hiten Pandya > >--- Marco Berizzi wrote: > > > Hi Hiten, > > > > > > Thanks for the reply about char & block devices. > > > Now all is much more clean. > > > >No Problem. > > > > > [ ... ] > > > > > > I haven't found anything about the difference > > > between cd0a & cd0c. > > > Any hints? > > > >OK. Ah my friend, it seems you didnt check the man pages (a very nice > >discovery :-). For information on 'cd' type devices, look at: > > > > 1) http://www.freebsd.org/cgi/man.cgi?query=cd&apropos=0&sektion=4 > > -- This man page contains information about SCSI CDROM Devices. > > > > 2) http://www.freebsd.org/cgi/man.cgi?query=ata&apropos=0&sektion=4 > > -- This man page contains information about ATAPI CDROM Devices. > > > >Hope this helps. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-newbies" in the body of the message