From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: nested raid possible? Date: Sat, 07 Jul 2007 10:12:32 -0400 Message-ID: <468F9F50.5040206@tmr.com> References: <8585506.1183693119573.JavaMail.root@wombat.diezmil.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <8585506.1183693119573.JavaMail.root@wombat.diezmil.com> Sender: linux-raid-owner@vger.kernel.org To: turbo@weasel.com Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids turbo@weasel.com wrote: > I have a raid-5 array of six 250gb hard drives. > I just bought four 500gb hard drives. > > I know I can take the six drives and make three raid-1 arrays of 500gb. > After doing that, can I make a raid-5 array consisting of the three > raid-0 arrays, and the four 500gb hard drives? > If you want performance and reliability, I would suggest migrating everything to RAID-10, which will handle unequal size drives reasonably well. In the medium term you may want to upgrade the 250=>500 just so you can reduce your spare drive needs. And if your storage needs are going to grow, you might consider winding up with RAID-6 and a hot spare. LVM offers another solution, which also adds complexity, and in my measurements hurts performance. The short answer is that you can do what you asked, but it's more complex and less reliable than is really desirable. -- bill davidsen CTO TMR Associates, Inc Doing interesting things with small computers since 1979