From: Kees Cook Subject: Re: [dm-devel] EXT4-fs error (device dm-42): ext4_mb_generate_buddy:741: group 1904, 32254 clusters in bitmap, 32258 in gd Date: Thu, 7 Jun 2012 16:38:31 -0700 Message-ID: References: <471046920.20120604234941@eikelenboom.it> <20120605000356.GM29466@outflux.net> <1018371644.20120605224154@eikelenboom.it> <20120605210806.GB7182@thunk.org> <1883708187.20120606090126@eikelenboom.it> <1482118647.20120606164012@eikelenboom.it> <20120607042756.GA30776@thunk.org> <20120607222729.GI6938@tux1.beaverton.ibm.com> <20120607225446.GK19839@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE To: "Ted Ts'o" , Kees Cook , djwong@us.ibm.com, Sander Eikelenboom , Linus Torvalds , dm-devel@redhat.com, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Received: from mail-bk0-f46.google.com ([209.85.214.46]:39754 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751008Ab2FGXid convert rfc822-to-8bit (ORCPT ); Thu, 7 Jun 2012 19:38:33 -0400 Received: by bkcji2 with SMTP id ji2so1132031bkc.19 for ; Thu, 07 Jun 2012 16:38:32 -0700 (PDT) In-Reply-To: <20120607225446.GK19839@thunk.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Jun 7, 2012 at 3:54 PM, Ted Ts'o wrote: > On Thu, Jun 07, 2012 at 03:40:40PM -0700, Kees Cook wrote: >> >> FWIW, I was building the filesystem that triggered this as ext4: >> >> =A0 mkfs.ext4 -T default -m 0 -O ^huge_file,^flex_bg -E >> discard,lazy_itable_init /dev/mapper/... > > Ouy of curiosity, was there a reason you chose those particular file > system parameters? =A0It's a surprising set, because if you're starti= ng > with a fresh file system, enabling flex_bg produces a more optimal > file system layout. The intent of this was to create a small (64M) initial filesystem as fast as possible that could be resized (to 3G) on the fly later. (The performance of the filesystem did not need to be optimized, just the speed of creation so that the create+mount would happen as fast as possible, to unblock things waiting for this filesystem to exist.) In the more common situation, it was built also with: -b 4096 ... -E ...,resize=3DMMM ... [device] NNN where MMM > NNN. And an online resize would be started a bit after it was created, growing it up to MMM. -Kees --=20 Kees Cook Chrome OS Security -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html