From owner-freebsd-questions@FreeBSD.ORG Wed May 10 10:00:30 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 6767F16A409 for ; Wed, 10 May 2006 10:00:30 +0000 (UTC) (envelope-from cknipe@savage.za.org) Received: from www16b.your-server.co.za (www16b.your-server.co.za [196.22.132.16]) by mx1.FreeBSD.org (Postfix) with ESMTP id F366B43D5E for ; Wed, 10 May 2006 10:00:05 +0000 (GMT) (envelope-from cknipe@savage.za.org) Received: from [127.0.0.1] (helo=localhost) by www16b.your-server.co.za with esmtp (Exim 4.52) id 1FdlU8-0000BZ-NA for freebsd-questions@freebsd.org; Wed, 10 May 2006 12:00:03 +0200 Received: from 196-207-40-213.gprs.vodacom.co.za (196-207-40-213.gprs.vodacom.co.za [196.207.40.213]) by default.your-server.co.za (IMP) with HTTP for ; Wed, 10 May 2006 12:00:00 +0200 Message-ID: <1147255200.4461b9a0a5e71@196.22.132.16> Date: Wed, 10 May 2006 12:00:00 +0200 From: cknipe@savage.za.org To: freebsd-questions@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit User-Agent: Internet Messaging Program (IMP) 3.2.5 X-Originating-IP: 196.207.40.213 Subject: OT: Torn between SCSI and SATA for RAID X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 May 2006 10:00:30 -0000 Hi, I've been spending the last couple of days extensively looking at various options for RAID and getting some storage system in place. Performance is not really a BIG issue, but I also don't want to have things hecticly slow either. This will be a NAS type of implementation so speed would be bound by relatively speaking slow network connections in any case... Now first things first as well, I did look at Fiber Channels too - and the tecnology is just to expensive and complex for a home type implementation that I want this for. Ideally, I'd like to start at 2TB of storage (yes, those movies must go somewhere!), but I'd like to be able to grow this as times go by... I also definately want redundancy on the data, as I just lost 80GB of precious data when ironically, a 160GB SATA Seagate went out under me. Now SCSI I know, is more expensive than SATA. Whether it provides beter performance than SATA I'm still uncertain off, but gut would tell me that due to the cost factor, SCSI *should* run away as far as speed is concerned. But also as I said previously, speed and performance is not a priority for my implementation and therefore it has very little weight. This makes me look at SATA then therefore. My problem with SATA, is the whole 1 Port, 1 Drive scenario. I've looked at the Adaptec 16 Port SATA Controller. The reviews I managed to get on that card on the Internet, paints a very grim picture. Buggered Firmware, the controller destroys drives, and general sluggish performance. Is anyone using this card that can perhaps give me a better picture? Given than the 16 Port (for now) is out of the question, I have a 8 Port, 4 Port and 2 Port (which isn't really worth looking at even) available to me. Now, even with a 8 Port card... Let's look at what I can achieve: Ports 1+2: 750GB Seagates (Biggest available), 1.5TB <- I'm short on my 2TB Initial Ports 3+4: Mirror of 1+2 Already, I am coming short of what I want to achieve, and I also have no expansion available to me for upgrades... With the 16 Port cards, what I want to achieve becomes quite possible, up to easy about 6TB of data - but I risk loosing drives *IF* what I read about the card is true. Also a gamble, considering the relatively high price of large SATA drives. Another thing that I read that I'm not completely sure about. Some of the Adaptec SCSI Cards advertises a max of 30 devices - some even more. Excuse the ignorance, but does the SCSI Bus not allow for a max of 8 devices? Do these cards then feature multiple buses to connect the cables to? If so, SATA will obviously not be able to provide something like this. Now comes my question... Uhm.. Can SATA RAID Controllers be 'linked'. Say, I but 4 x 8-Port Adaptec SATA RAID Controllers... 2 x 8 Port Cards = 16 Ports for 1 RAID 5 Array (@ 750GB Drives, 12TB Max). The other 2 cards, to mirror. I know that I can use one Controller to mirror another, but can I extend a array across multiple controllers... And then naturally, just HOW much slower does the array function? I've seen some comments and posts (esp. on slashdot) made where people go about running massive arrays successfully on SATA. Given the limits on the Ports at the controller, just how is this achieved? Sorry that this is so OT, but I hope I'd get some good answers. This is definately not something that's been discussed allot before considering the amount of info I got after spending a number of days on google... -- Chris.