From owner-freebsd-questions@FreeBSD.ORG Sat Oct 17 22:17:31 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 91C5E1065676 for ; Sat, 17 Oct 2009 22:17:31 +0000 (UTC) (envelope-from vince@unsane.co.uk) Received: from ostracod.unsane.co.uk (unsane-pt.tunnel.tserv5.lon1.ipv6.he.net [IPv6:2001:470:1f08:110::2]) by mx1.freebsd.org (Postfix) with ESMTP id E4F078FC21 for ; Sat, 17 Oct 2009 22:17:30 +0000 (UTC) Received: from vhoffman-macbook.local ([10.0.0.173]) (authenticated bits=0) by ostracod.unsane.co.uk (8.14.3/8.14.3) with ESMTP id n9INHksf030161 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 18 Oct 2009 23:17:46 GMT (envelope-from vince@unsane.co.uk) Message-ID: <4ADA4279.4080006@unsane.co.uk> Date: Sat, 17 Oct 2009 23:17:29 +0100 From: Vincent Hoffman User-Agent: Thunderbird 2.0.0.23 (Macintosh/20090812) MIME-Version: 1.0 To: PJ References: <4AD8EB8F.9010900@videotron.ca> <4AD95740.6010408@gmail.com> <4ADA3D48.70307@videotron.ca> In-Reply-To: <4ADA3D48.70307@videotron.ca> X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: michael , freebsd-questions@freebsd.org Subject: Re: I hate to bitch but bitch I must X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 17 Oct 2009 22:17:32 -0000 PJ wrote: > michael wrote: > >> PJ wrote: >> >>> Why is it that the manual pages, as thorough as they may be, are very, >>> very confusing. >>> Perhaps I am being too wary, but I find that too many >>> instructions/examples are stumbling blocks to appreciation of the whole >>> system: >>> for instance, let's look at the instructions for changing disk labels >>> with glabel or is it tunefs ? >>> man glabel(8): >>> >>> for UFS the file system label is set with >>> tunefs(8) >>> . >>> >>> what happened to glabel? >>> man tunefs(8) >>> The *tunefs* utility cannot be >>> run on an active file system. To change an active file system, it must >>> be downgraded to read-only or unmounted. >>> >>> So, you have to run tunefs from an active file system to modify another >>> disk? >>> but from man tunefs: >>> BUGS >>> This utility should work on active file systems. >>> What in hades does this mean--just above it says cannot be run on active >>> file systems. ??? >>> To change the root file >>> system, the system must be rebooted after the file system is tuned. >>> >>> You can tune a file system, but you cannot tune a fish. >>> How cute... And fish eat bugs. >>> >>> Seriously, now to the manual: >>> To create a permanent label for a UFS2 file system without destroying >>> any data, issue the following command: >>> # tunefs -L /home/ /dev/da3 >>> >>> Oh? home is what? What does this have to do with the partitions? >>> Here's from man glabel(8): >>> >>> EXAMPLES >>> The following example shows how to set up a label for disk ``da2'', cre- >>> ate a file system on it, and mount it: >>> glabel label -v usr /dev/da2 >>> newfs /dev/label/usr >>> mount /dev/label/usr /usr >>> [...] >>> umount /usr >>> glabel stop usr >>> glabel unload >>> >>> The next example shows how to set up a label for a UFS file system: >>> tunefs -L data /dev/da4s1a >>> mount /dev/ufs/data /mnt/data >>> >>> Am I to understand that glabel is only for a new system? What's with the >>> newfs... I'm trying to set labels on an system that is already set up. >>> And, the glabel examle above is not for UFS file systems? Oh, that's for >>> tunefs? >>> So why are we even dealing with this glabel? >>> >>> from manual: >>> # tunefs -L /home/ //dev/da3/ >>> A label should now exist in /dev/ufs which may be added to /etc/fstab: >>> /dev/ufs/home /home ufs rw 2 2 >>> >>> Why? Is this necessary? and somewhere I saw "tunefs -L volume >>> /dev/da0s1a" or something like that. Does that mean that each partition >>> should be tunefsd? Maybe the guys who programmed this stuff understand; >>> I sure don't. I just want to be able to set the labels according to what >>> they say can be done... so shy not have a clear and concise explanation? >>> >>> Do people who write this stuff ever read it? Tell me that its clear and >>> simple and to the point... so far, I have been running back and forth >>> between half a dozen web pages trying to understand what is going >>> on... and doing things through a dense fog does not produce creative >>> results! >>> _______________________________________________ >>> freebsd-questions@freebsd.org mailing list >>> http://lists.freebsd.org/mailman/listinfo/freebsd-questions >>> To unsubscribe, send any mail to >>> "freebsd-questions-unsubscribe@freebsd.org" >>> >>> >> ok, in short since i didn't see anyone answer this directly, your >> question of tunefs vs glabel: >> >> tunefs is for UFS: it labels a UFS filesystem, no matter the device, >> ie: ad or da. tunefs is part of the filesystem utilities for UFS. >> good example, can't tunefs -L SWAP /dev/ad0s1b if it is a swap. you >> can glabel it. >> >> glabel is for labeling a device itself. you can glabel an ntfs >> filesystem or ext2, whatever. >> >> >> > Thanks for that, Michael. > But can you explain what this means? It just is not clear for me. > "# tu;nefs -L home /dev/da3" > This puts a label on that disk? So now it can be referred to as home? > da3 = home ? > > yes. this makes a ufs label which you can access via /dev/ufs for example (my home system) jhary@ostracod (23:08:34 <~>) 0 $ ls /dev/ufs SCRATCH SSDROOT SSDUSR SSDVAR jhary@ostracod (23:08:39 <~>) 0 $ mount /dev/ufs/SSDROOT on / (ufs, local, noatime) devfs on /dev (devfs, local, multilabel) /dev/ufs/SSDUSR on /usr (ufs, local, noatime, soft-updates) /dev/ufs/SSDVAR on /var (ufs, local, noatime, soft-updates) /dev/ufs/SCRATCH on /scratch (ufs, local, noatime, gjournal) tmpfs on /tmp (tmpfs, local) devfs on /var/named/dev (devfs, local, multilabel) jhary@ostracod (23:08:41 <~>) 0 $ cat /etc/fstab /dev/ufs/SSDROOT / ufs rw,noatime 1 1 /dev/ufs/SSDUSR /usr ufs rw,noatime 2 2 /dev/ufs/SSDVAR /var ufs rw,noatime 2 2 /dev/label/SWAP none swap sw 0 0 /dev/ufs/SCRATCH /scratch ufs rw,noatime 2 2 tmpfs /tmp tmpfs rw 0 0 note there I have also used glabel on the swap (command used was glabel label /dev/ad10p1) One thing to note with label, if you mount/use the device by is raw node, the label disapears. ie: [root@ostracod ~]# swapoff -a swapoff: removing /dev/label/SWAP as swap device [root@ostracod ~]# swapon /dev/ad10p1 [root@ostracod ~]# ls /dev/label/ [root@ostracod ~]# swapoff /dev/ad10p1 [root@ostracod ~]# ls /dev/label/ SWAP [root@ostracod ~]# swapon -a swapon: adding /dev/label/SWAP as swap device This used to confuse me greatly :) Vince > I'll try to delve into the man glabel further... but things still look > murky. > > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org" >