From: Andreas Dilger Subject: Re: [PATCH] fix up lazy_bg bitmap initialization at mkfs time Date: Fri, 20 Apr 2007 04:10:20 -0600 Message-ID: <20070420101020.GQ5967@schatzie.adilger.int> References: <4627DA21.7050002@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: ext4 development To: Eric Sandeen Return-path: Received: from mail.clusterfs.com ([206.168.112.78]:48849 "EHLO mail.clusterfs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754183AbXDTKKW (ORCPT ); Fri, 20 Apr 2007 06:10:22 -0400 Content-Disposition: inline In-Reply-To: <4627DA21.7050002@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Apr 19, 2007 16:07 -0500, Eric Sandeen wrote: > While trying out the -O lazy_bg option, I ran into some trouble on my > big filesystem. The journal size was > free blocks in the first block group, > so it spilled into the next bg with available blocks. Since we are using > lazy_bg here, that -should- have been the last block group. Just as an FYI - it probably makes little sense to have a 128MB journal for a filesystem you want to use for testing, since it would still write 128MB to your loopback device when zeroing the journal. It still makes sense for mke2fs and libext2fs to be fixed for correctness, but I think it also makes sense for lazy_bg to influence the journal size. > Unfortunately it also increases mkfs time a bit, as it must search > a huge string of unavailable blocks if it has to allocate in the > last bg. Ah well... It also probably makes sense for libext2fs to check group descriptors while allocating... Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc.