From owner-freebsd-hackers@FreeBSD.ORG Tue Jul 15 06:08:44 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E6C1B1065673 for ; Tue, 15 Jul 2008 06:08:44 +0000 (UTC) (envelope-from doconnor@gsoft.com.au) Received: from cain.gsoft.com.au (cain.gsoft.com.au [203.31.81.10]) by mx1.freebsd.org (Postfix) with ESMTP id 252228FC1C for ; Tue, 15 Jul 2008 06:08:43 +0000 (UTC) (envelope-from doconnor@gsoft.com.au) Received: from inchoate.gsoft.com.au (inchoate.gsoft.com.au [203.31.81.30]) (authenticated bits=0) by cain.gsoft.com.au (8.13.8/8.13.8) with ESMTP id m6F68dmO076846 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Tue, 15 Jul 2008 15:38:39 +0930 (CST) (envelope-from doconnor@gsoft.com.au) From: "Daniel O'Connor" To: freebsd-hackers@freebsd.org Date: Tue, 15 Jul 2008 15:38:36 +0930 User-Agent: KMail/1.9.7 References: <482257ad0807141106m679ec19frd853339637d27a2d@mail.gmail.com> <200807151302.30415.doconnor@gsoft.com.au> <482257ad0807142138j1f7b7dd8nda7de865a4616fc0@mail.gmail.com> In-Reply-To: <482257ad0807142138j1f7b7dd8nda7de865a4616fc0@mail.gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart2266764.zHTSuDn3IL"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200807151538.38285.doconnor@gsoft.com.au> X-Spam-Score: -3.977 () ALL_TRUSTED,BAYES_00 X-Scanned-By: MIMEDefang 2.63 on 203.31.81.10 Cc: Tapan Chaudhari Subject: Re: Can I change the device of the "/" mount point at boot time. X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 15 Jul 2008 06:08:45 -0000 --nextPart2266764.zHTSuDn3IL Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Tue, 15 Jul 2008, Tapan Chaudhari wrote: > Thanks Deniel for the reply. I am aware of the fact you mentioned > and will keep in mind. > Well what i am trying to achieve is a simple thing to write an > interception driver to catch all the i/os going to a particular > device, do some manipulations on it and than let it through to the > original device. Well as you mentioned about geom, I have recently > posted a mail on GEOM mailing list as I could not find geom doing > interception, the discussion is still on (You can see the mails with > subject line "Can GEOM be used to intercept the I/o calls to an > existing mounted device?"). Any sugessuions on interception driver > will be helpful? My first question would be "Why do you want to do that?" > As an interception driver is not possible, for time being I am going > towards the redirection concept which will require a reboot and > changing the devices on the mount points. For redirection driver, I > dont think I will need geom. I can directly create a new device. > Rather I think it would be an overhead using geom for a virtual > device. > Any thoughts on both the issues? I think you'd have a lower overhead and much less hassle writing a GEOM=20 class and using that. =2D-=20 Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C --nextPart2266764.zHTSuDn3IL Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.8 (FreeBSD) iD8DBQBIfD7m5ZPcIHs/zowRAnE3AJ4sguOAy6lCvyQhkhBi6Z8yPixvrACfQwOf 5U/rRk0EOolbyJxy3TzGZMo= =YVqG -----END PGP SIGNATURE----- --nextPart2266764.zHTSuDn3IL--