From mboxrd@z Thu Jan 1 00:00:00 1970 From: berk walker Subject: Re: Changing chunk size Date: Sat, 17 Feb 2007 20:51:40 -0500 Message-ID: <45D7B12C.4010109@panix.com> References: <45D4955C.60008@tmr.com> <17876.60347.983953.748979@notabene.brown> <45D5E05E.4000706@tmr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <45D5E05E.4000706@tmr.com> Sender: linux-raid-owner@vger.kernel.org To: Bill Davidsen Cc: Neil Brown , Linux RAID List-Id: linux-raid.ids Bill Davidsen wrote: > Neil Brown wrote: >> On Thursday February 15, davidsen@tmr.com wrote: >> >>> I have determined that a large array was created with an >>> overly-large chunk size. Best way to resize? >>> >> >> Dump and restore. >> >> in-place reshapes (such as raid5 + 1 disk => raid6 or >> change-chunk-size) are on my list of 'that might be interesting to >> implement', but there are plenty of more interesting things. And it >> would be very slow. It would need to copy some number of stripes to a >> backup somewhere, then copy them back in the new layout, so every >> block in the array would be written twice. > I'm sure "slow" is a relative term, compared to backing up TBs of data > and trying to restore them. Not to mention the lack of inexpensive TB > size backup media. That's totally unavailable at the moment, I'll live > with what I have, thanks. > If you were to be a gambler, Bill - Get 2 disks big enough to store > your data, create a RAID5 mising one, and copy over the data. Re do > the original array, and copy back. Yeah, $0.02 doesn't buy much anymore. Besides, you'll be needing bigger disks for the next machine you build,eh? b-