From mboxrd@z Thu Jan  1 00:00:00 1970
From: Chris Mason <chris.mason@oracle.com>
Subject: Re: btrfs device management
Date: Mon, 09 Jun 2008 09:52:51 -0400
Message-ID: <1213019571.10187.12.camel@think.oraclecorp.com>
References: <62325.68.145.107.21.1212882817.squirrel@avalon.arbitraryconstant.com>
	 <20080609064358.GA27849@infradead.org>
	 <20080609060609.01e5c1d6@think.oraclecorp.com>
	 <f058a9c30806090645t12ad82f6pcb52c12a038897ed@mail.gmail.com>
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Cc: Christoph Hellwig <hch@infradead.org>,
	btrfs-devel@arbitraryconstant.com, linux-btrfs@vger.kernel.org
To: Miguel Sousa Filipe <miguel.filipe@gmail.com>
Return-path: <linux-btrfs-owner@vger.kernel.org>
In-Reply-To: <f058a9c30806090645t12ad82f6pcb52c12a038897ed@mail.gmail.com>
List-ID: <linux-btrfs.vger.kernel.org>

On Mon, 2008-06-09 at 14:45 +0100, Miguel Sousa Filipe wrote:
> Hi all,
> 
> On Mon, Jun 9, 2008 at 11:06 AM, Chris Mason <chris.mason@oracle.com> wrote:
> > On Mon, 9 Jun 2008 02:43:58 -0400
> > Christoph Hellwig <hch@infradead.org> wrote:
> >
> >> On Sat, Jun 07, 2008 at 05:53:37PM -0600,
> >
> >> Yes, I plan to work on adding properly designed multiple device
> >> support for btrfs and my upcoming similar xfs work.  I'll live in
> >> good old mount and libvolume_id.
> >>
> >
> > I won't say no to a mount patch either.  The only downside is that
> > we'll need to update it (in mount) as the format goes through changes
> > over the summer.  But that is a temporary problem.
> 
> 
> I believe that a multi-volume filesystem should have some kind of
> human understandable handle/name.
> Just like a name of a logical volume. For single disks filesystems,
> the disk name suffices (and reduced the need for such a name/label),
> but in multi-disk FS there should still be a humane name for that
> mountpoint or filesystem.
> So, while any unique identifier would technically be okay, I think
> that there should be a human undertanble name/label for it. Not just
> some uid.
> 
> Does Hellwig work, or any planned feature provide this ?

mkfs.btrfs already has a way to set the label of the filesystem.
mkfs.btrfs -L label /dev/xxxx

btrfs-show will show you the labels of any existing filesystems.

In practice, anyone on a san really wants to use uuids.  Labels are nice
until two people on the same san create a filesystem named system, and
then it all gets ugly ;)

-chris