From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jeff Garzik <jeff@garzik.org>
Subject: Re: [RFC 0/13] extents and 48bit ext3
Date: Fri, 09 Jun 2006 19:44:44 -0400
Message-ID: <448A07EC.6000409@garzik.org>
References: <44898EE3.6080903@garzik.org> <448992EB.5070405@garzik.org>	
	<Pine.LNX.4.64.0606090836160.5498@g5.osdl.org>
	<448997FA.50109@garzik.org>	 <m3irnacohp.fsf@bzzz.home.net>
	<44899A1C.7000207@garzik.org>	 <m3ac8mcnye.fsf@bzzz.home.net>
	<4489B83E.9090104@sbcglobal.net>	
	<20060609181426.GC5964@schatzie.adilger.int>
	<4489C34B.1080806@garzik.org>	 <20060609194959.GC10524@thunk.org>
	<4489D44A.1080700@garzik.org>	
	<1149886670.5776.111.camel@sisko.sctweedie.blueyonder.co.uk>	
	<4489ECDD.9060307@garzik.org>
	<1149890138.5776.114.camel@sisko.sctweedie.blueyonder.co.uk>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Cc: Andrew Morton <akpm@osdl.org>, Theodore Ts'o <tytso@mit.edu>,
	Matthew Frost <artusemrys@sbcglobal.net>,
	"ext2-devel@lists.sourceforge.net" <ext2-devel@lists.sourceforge.net>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Linus Torvalds <torvalds@osdl.org>, Mingming Cao <cmm@us.ibm.com>,
	linux-fsdevel@vger.kernel.org, Alex Tomas <alex@clusterfs.com>
Return-path: <ext2-devel-bounces@lists.sourceforge.net>
To: "Stephen C. Tweedie" <sct@redhat.com>
In-Reply-To: <1149890138.5776.114.camel@sisko.sctweedie.blueyonder.co.uk>
List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/ext2-devel>,
	<mailto:ext2-devel-request@lists.sourceforge.net?subject=unsubscribe>
List-Archive: <http://sourceforge.net/mailarchive/forum.php?forum=ext2-devel>
List-Post: <mailto:ext2-devel@lists.sourceforge.net>
List-Help: <mailto:ext2-devel-request@lists.sourceforge.net?subject=help>
List-Subscribe: <https://lists.sourceforge.net/lists/listinfo/ext2-devel>,
	<mailto:ext2-devel-request@lists.sourceforge.net?subject=subscribe>
Sender: ext2-devel-bounces@lists.sourceforge.net
Errors-To: ext2-devel-bounces@lists.sourceforge.net
List-Id: linux-fsdevel.vger.kernel.org

Stephen C. Tweedie wrote:
> Hi,
> 
> On Fri, 2006-06-09 at 17:49 -0400, Jeff Garzik wrote:
> 
>>>> Consider a blkdev of size S1.  Using LVM we increase that value under 
>>>> the hood to size S2, where S2 > S1.  We perform an online resize from 
>>>> size S1 to S2.  The size and alignment of any new groups added will 
>>>> different from the non-resize case, where mke2fs was run directly on a 
>>>> blkdev of size S2.
>>> No, they won't.  We simply grow the last block group in the filesystem
>>> up to the size where we'd naturally add another block group anyway; and
>>> then, we add another block group exactly where it would have been on a
>>> fresh mkfs.
>> Yes but the inodes per group etc. would differ.
> 
> No, we add the same number of inodes in the new groups that all the
> previous groups have.

Yes.  Re-read what I wrote.  To put it another way, "mkfs S1 + resize to 
S2" does not produce precisely the same layout as "mkfs S2".

	Jeff