From owner-freebsd-questions@FreeBSD.ORG Thu Mar 24 15:51:05 2005 Return-Path: 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 8B6CF16A4CE for ; Thu, 24 Mar 2005 15:51:05 +0000 (GMT) Received: from scorpion.eng.ufl.edu (scorpion.eng.ufl.edu [128.227.116.10]) by mx1.FreeBSD.org (Postfix) with SMTP id EAFD443D5C for ; Thu, 24 Mar 2005 15:51:04 +0000 (GMT) (envelope-from bob89@eng.ufl.edu) Received: (qmail 25554 invoked from network); 24 Mar 2005 15:51:04 -0000 Received: from scanner.engnet.ufl.edu (HELO ?128.227.152.221?) (128.227.152.221) by scorpion.eng.ufl.edu with SMTP; 24 Mar 2005 15:51:04 -0000 Message-ID: <4242E1E8.1090602@eng.ufl.edu> Date: Thu, 24 Mar 2005 10:51:04 -0500 From: Bob Johnson Organization: University of Florida User-Agent: Mozilla Thunderbird 1.0 (X11/20050316) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Odhiambo Washington References: <20050324151935.GA10374@ns2.wananchi.com> In-Reply-To: <20050324151935.GA10374@ns2.wananchi.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit cc: freebsd-questions@freebsd.org Subject: Re: RFC 2005 - mounting two slices from 2 different disks to same mount point ;) X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 24 Mar 2005 15:51:05 -0000 Odhiambo Washington wrote: >Hello Gang! > >On FreeBSD 5.3-RELEASE, we have mounted slices as follows: > >-bash-2.05b$ mount >/dev/ad0s3a on / (ufs, local) >devfs on /dev (devfs, local) >/dev/ad0s3e on /tmp (ufs, local, soft-updates) >/dev/ad0s3f on /usr (ufs, local, soft-updates) >/dev/ad0s3d on /var (ufs, local, soft-updates) >devfs on /var/named/dev (devfs, local) >/dev/ad0s5 on /drive_d (msdosfs, local) >/dev/ad3s1d on /tmp (ufs, local, soft-updates) > > >/dev/ad0s3e was 500MB >/dev/ad3s1d was 40GB > >In /etc/fstab, we specified the mount point for both to /tmp. > >We then wrote a 1GB file to /tmp and there was no error. The >file was successfully written. > >Can an expert with disks tell me where the file was written? >How did the system decide where to write the file? How did it >"select" /tmp in this case? > > > It was written to the last disk you mounted. When you mount a disk, it replaces whatever was mounted there previously. At least, that's what the mount docs say, I didn't actually try to test it. If you do a df it should show that /tmp has the capacity of the last drive you mounted there. Try mounting the 40GB drive first and then the 500 MB drive and run your test again. >Linux guys have talked about "disk spanning" using the method >we just tested. I am wondering the dangers I face doing such >a thing!! > > > If you want to span disks, take a look at gconcat(8) or vinum(8). gconcat replaces an older utility I don't remember the name of at the moment. >Happy Easter to ye all!! > > >-Wash > > - Bob