From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sam Vilain Subject: Re: How to build a big file server Date: Fri, 6 Jun 2003 01:43:13 +1200 Sender: Sam Vilain Message-ID: <200306060143.13516.sam@vilain.net> References: <1054800852.1997.15.camel@wusel.schnulli.de> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <1054800852.1997.15.camel@wusel.schnulli.de> Content-Disposition: inline List-Id: Content-Type: text/plain; charset="us-ascii" To: Heinz-Josef Claes Cc: reiserfs-list@namesys.com On Thu, 05 Jun 2003 20:14, Heinz-Josef Claes wrote: > - I plan to build a system with IDE 250GB drives. 7 of them for raid 5 > and one hot spare. The OS will be on separate hardware raid 1 on smaller > disks. Does anybody have experience with IDE controlers for the big > disks? Is it better to use hardware raid oder software raid > (performance)? Yes, if massive disk space at virtually no cost is what you're after, it has to be IDE. But, you don't have to give up the benefits of a servicable data centre. Check out http://www.acme-technology.co.uk/ for some fairly snazzy hot swap IDE rack mount enclosures, cases and more. There must be other vendors out there, too. If you've got that many disks, you NEED hot swap! As for the software RAID vs hardware RAID, my experience is that software RAID 1 can deliver the same amount of disk space as hardware RAID 5 for less total cost, factoring in the price of the RAID controller. Of course, your storage density is worse for RAID 1, but you could probably still fit your 10TB into a single rack, assuming you can get 8 disks in a 3U chassis. RAID 1 in any form will *always* outperform RAID 5, especially in the event of a failure. RAID 1 arrays hardly notice, RAID 5 arrays slow to a crawl. btw, I wouldn't necessarily be too worried about stacking too many devices on a single chain. Benchmark heavily all configurations with a workload and close to the real workload of the device before buying dozens of controllers, or settling on one plan recommended by some self-professed `expert' trolling the reiserfs-list. Your bottleneck may not be where you think. I'd also strongly suggest getting a motherboard with 64 bit and/or 66MHz PCI bus. The Tyan ThunderK7 is pretty good - a dual capable Athlon board that's stable as hell, and you can run the OpenBIOS project on it - manage your servers with a serial terminal server (eg, a PC with a serial breakout card) instead of a dumbass KVM switch. Then, you'd have something that's almost as good as a commerical UNIX platform, but not really. Personally, I'd get a quote for the arrays running on Sparc hardware from http://www.anysystem.com/ (used Sun parts peddlers) and offer that as a comparison. Running LVM to allocate a large RAID volume works exceedingly well from a system administration standpoint, especially with reiserfs. It's online resizing support is second to none. -- Sam Vilain, sam@vilain.net Humanity is acquiring all the right technology for all the wrong reasons. -- R. Buckminster Fuller