From owner-freebsd-geom@FreeBSD.ORG Fri Jul 11 18:29:10 2008 Return-Path: Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EA358106566B for ; Fri, 11 Jul 2008 18:29:10 +0000 (UTC) (envelope-from tapan.list@gmail.com) Received: from qb-out-0506.google.com (qb-out-0506.google.com [72.14.204.235]) by mx1.freebsd.org (Postfix) with ESMTP id 9ADA28FC08 for ; Fri, 11 Jul 2008 18:29:10 +0000 (UTC) (envelope-from tapan.list@gmail.com) Received: by qb-out-0506.google.com with SMTP id q12so395987qbq.13 for ; Fri, 11 Jul 2008 11:29:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:in-reply-to:mime-version:content-type:references; bh=nQk0nVg2S88l93HtiFccP1Sj47No4TrOM4aDDdwQCmk=; b=TB8TxRV/og1VEa1HRwzykHD0GI0T6AuIF57dxS2sVntAxxwJtIGnZoMVmTP99KStPR RenN9HrQxcD79ZNgMruqK9lzPMrVJEl3xw3wBF0YLEnXG6oE1B1DhcCqcPFI7uPzd9bB bN2gWQ+U9pYubwlOLJXKThzKxH6iVCHcmdsTA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:in-reply-to:mime-version :content-type:references; b=Wm4XmvD0EEJXE+VjoXDV30bZadj8tZR8ULW0XcikKzWbg3uaAwGdcV40kKok5PTN5n QDQvAPgOUzSX7cLdJT5KkIdYMdbnt8xX2ShBwfxWu3citmVl8LZ88kIFDRM86Fn+YRMZ ok2RQ0t2hBjPUHj7gZFnHqt0KQCQoO6blAVgI= Received: by 10.103.222.12 with SMTP id z12mr5649257muq.12.1215800949167; Fri, 11 Jul 2008 11:29:09 -0700 (PDT) Received: by 10.103.227.19 with HTTP; Fri, 11 Jul 2008 11:29:09 -0700 (PDT) Message-ID: <482257ad0807111129i66ac4372sbc9b4d4ef7675e9d@mail.gmail.com> Date: Fri, 11 Jul 2008 23:59:09 +0530 From: "Tapan Chaudhari" To: freebsd-geom@freebsd.org In-Reply-To: <482257ad0807100655u1a5c660awfad05564e40e9a95@mail.gmail.com> MIME-Version: 1.0 References: <482257ad0807100541s2d2c3d1eo6cd57c3a1bc338d1@mail.gmail.com> <200807102309.03191.mark@legios.org> <482257ad0807100655u1a5c660awfad05564e40e9a95@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Subject: Re: Can GEOM be used to intercept the I/o calls to an existing mounted device? X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 11 Jul 2008 18:29:11 -0000 Hey guys, First of all, I was not able to receive your replies to my mail. I don't know the reason but I am already subscribed to the list. I got to know about your replies from the digest i received today. I have written a mail to the mailing list owner describing this problem. Hope this does not happen again. Well regarding GEOM as Poul mentioned he has already done this interception mechanism in GEOM, Poul can you please help me out by giving some directions as to how to move ahead and implement the interceptions of i/o to a particular device? I would be really happy to get any help regarding the interception mechanism. Thanks, --Tapan. On Thu, Jul 10, 2008 at 7:25 PM, Tapan Chaudhari wrote: > Thanks Mark, but unmounting will anyways work. But the problem here will > be, a new device "/dev/mirror/gm0" and "/dev/mirror/gm0s1" will be created > after :- > > #gmirror label -v -n -b round-robin gm0 /dev/md0 > #gmirror load > #gmirror configure -a gm0 > > and "/dev/md0s1" gets deleted. > Now I will have to mount the new device "/dev/mirror/gm0s1" to get my > original contents. > Can't I do it on the fly while the device is already mounted? I just want > that all the calls going to the device "/dev/md0s1" first come to me and > then it goes to the original device. In short intercepting the i/o calls. Is > there some way I can achieve this? > > Thanks, > > > On Thu, Jul 10, 2008 at 6:39 PM, Mark Gladman wrote: > >> On Thursday 10 July 2008 22:41:25 Tapan Chaudhari wrote: >> > Hi All, >> > I am a newbie to FreeBSD and GEOM. I wanted to intercept the i/o >> calls >> > going to a particular mounted device by writing some driver. >> > I came across geom and thought it might work. I tried to create a new >> > device, mount it and then tried using gmirror to mirror the device :- >> > >> > #dd if=/dev/zero of=file1 bs=1M count=10 >> > #dd if=/dev/zero of=file2 bs=1M count=10 >> > #mdconfig -f file1 >> > #mdconfig -f file2 >> > #fdisk -B /dev/mirror/md0 >> > #newfs /dev/mirror/md0s1 >> > #mkdir /mnt/mirror0 >> > #mount /dev/mirror/md0s1 /mnt/mirror0/ >> > >> > #gmirror label -v -n -b round-robin gm0 /dev/md0 >> > gmirror: Can't store metadata on /dev/md0: Operation not permitted. >> > >> > It gave me this error "gmirror: Can't store metadata on /dev/md0: >> Operation >> > not permitted." >> > >> > Am I doing something wrong? Or GEOM does not permit me intercept the i/o >> > calls? If not geom, is there any other mechanism by which I can achieve >> it? >> > >> > >> > Thanks, >> > --Tapan. >> > _______________________________________________ >> > freebsd-geom@freebsd.org mailing list >> > http://lists.freebsd.org/mailman/listinfo/freebsd-geom >> > To unsubscribe, send any mail to "freebsd-geom-unsubscribe@freebsd.org" >> >> Hey, >> >> You're attempting to set up gmirror on a mounted device. >> Unmount /dev/mirror/md0s1 then retry the gmirror command and it should >> work. >> >> Cheers! >> Mark >> > >