From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thiemo Nagel Subject: Re: Raid over 48 disks Date: Tue, 18 Dec 2007 20:34:08 +0100 Message-ID: <476820B0.9010200@ph.tum.de> References: <00EF99B2-3BCC-4D75-BC75-8F256B0A2476@gmail.com> Reply-To: thiemo.nagel@ph.tum.de 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: Norman Elton Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Dear Norman, >> 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? >> >> Are we crazy to think this is even possible? I'm running 22x 500GB disks attached to RocketRaid2340 and NFORCE-MCP55 onboard controllers on an Athlon DC 5000+ with 1GB RAM: 9746150400 blocks super 1.2 level 6, 256k chunk, algorithm 2 [22/22] Performance of the raw device is fair: # dd if=/dev/md2 of=/dev/zero bs=128k count=64k 65536+0 records in 65536+0 records out 8589934592 bytes (8.6 GB) copied, 15.6071 seconds, 550 MB/s Somewhat less through ext3 (created with -E stride=64): # dd if=largetestfile of=/dev/zero bs=128k count=64k 65536+0 records in 65536+0 records out 8589934592 bytes (8.6 GB) copied, 26.4103 seconds, 325 MB/s There were no problems up to now. (mkfs.ext3 wants -F to create a filesystem larger than 8TB. The hard maximum is 16TB, so you will need to create partitions, if your drives are larger than 350GB...) Kind regards, Thiemo Nagel