From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Tokarev Subject: Re: Converting Ext3 to Ext3 under RAID 1 Date: Thu, 03 Aug 2006 11:50:24 +0400 Message-ID: <44D1AAC0.9080009@tls.msk.ru> References: <200607152056.55090.pwaldo@waldoware.com> <200607230753.47853.pwaldo@waldoware.com> <17603.25777.274507.385333@cse.unsw.edu.au> <200607230832.48807.pwaldo@waldoware.com> <17605.22207.56022.972200@cse.unsw.edu.au> <44D0FD9F.9070605@steeleye.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <44D0FD9F.9070605@steeleye.com> Sender: linux-raid-owner@vger.kernel.org To: Paul Clements Cc: Dan Graham , linux-raid@vger.kernel.org List-Id: linux-raid.ids Paul Clements wrote: >> Is 16 blocks a large enough area? > > Maybe. The superblock will be between 64KB and 128KB from the end of the > partition. This depends on the size of the partition: > > SB_LOC = PART_SIZE - 64K - (PART_SIZE & (64K-1)) > > So, by 16 blocks, I assume you mean 16 filesystem blocks (which are > generally 4KB for ext3). So as long as your partition ends exactly on a > 64KB boundary, you should be OK. > > Personally, I would err on the safe side and just shorten the filesystem > by 128KB. It's not like you're going to miss the extra 64KB. Or, better yet, shrink it by 1Mb or even 10Mb, whatever, convert to raid, and - the point - resize it to the max size of the raid device (ie, don't give "size" argument to resize2fs). This way, you will be both safe and will use 100% of the available size. /mjt