From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: Raid over 48 disks Date: Wed, 19 Dec 2007 10:26:31 -0500 Message-ID: <47693827.6070604@tmr.com> References: <00EF99B2-3BCC-4D75-BC75-8F256B0A2476@gmail.com> <18280.11620.381726.737353@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Mattias Wadenstein Cc: Neil Brown , Norman Elton , linux-raid@vger.kernel.org List-Id: linux-raid.ids Mattias Wadenstein wrote: > On Wed, 19 Dec 2007, Neil Brown wrote: > >> On Tuesday December 18, normelton@gmail.com wrote: >>> We're investigating the possibility of running Linux (RHEL) on top of >>> Sun's X4500 Thumper box: >>> >>> http://www.sun.com/servers/x64/x4500/ >>> >>> Basically, it's a server with 48 SATA hard drives. No hardware RAID. >>> It's designed for Sun's ZFS filesystem. >>> >>> So... we're curious how Linux will handle such a beast. Has anyone run >>> MD software RAID over so many disks? Then piled LVM/ext3 on top of >>> that? Any suggestions? > > There are those that have run Linux MD RAID on thumpers before. I > vaguely recall some driver issues (unrelated to MD) that made it less > suitable than solaris, but that might be fixed in recent kernels. > >> Alternately, 8 6drive RAID5s or 6 8raid RAID6s, and use RAID0 to >> combine them together. This would give you adequate reliability and >> performance and still a large amount of storage space. > > My personal suggestion would be 5 9-disk raid6s, one raid1 root mirror > and one hot spare. Then raid0, lvm, or separate filesystem on those 5 > raidsets for data, depending on your needs. Other than thinking raid-10 better than raid-1for performance, I like it. > > You get almost as much data space as with the 6 8-disk raid6s, and > have a separate pair of disks for all the small updates (logging, > metadata, etc), so this makes alot of sense if most of the data is > bulk file access. -- Bill Davidsen "Woe unto the statesman who makes war without a reason that will still be valid when the war is over..." Otto von Bismark