From owner-freebsd-fs@FreeBSD.ORG Wed Aug 6 00:03:54 2008 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EAAAE106566C for ; Wed, 6 Aug 2008 00:03:54 +0000 (UTC) (envelope-from morganw@chemikals.org) Received: from cdptpa-omtalb.mail.rr.com (cdptpa-omtalb.mail.rr.com [75.180.132.123]) by mx1.freebsd.org (Postfix) with ESMTP id A75AD8FC15 for ; Wed, 6 Aug 2008 00:03:54 +0000 (UTC) (envelope-from morganw@chemikals.org) Received: from shop.chemikals.org ([75.182.7.127]) by cdptpa-omta05.mail.rr.com with ESMTP id <20080806000353.PXZQ18001.cdptpa-omta05.mail.rr.com@shop.chemikals.org> for ; Wed, 6 Aug 2008 00:03:53 +0000 Received: from volatile.chemikals.org (root@r74-193-170-223.bssrcmta01.bscyla.by.dh.suddenlink.net [74.193.170.223] (may be forged)) by shop.chemikals.org (8.14.2/8.14.2) with ESMTP id m7603qn6052673 for ; Tue, 5 Aug 2008 20:03:52 -0400 (EDT) (envelope-from morganw@chemikals.org) Received: from localhost (morganw@localhost [127.0.0.1]) by volatile.chemikals.org (8.14.2/8.14.2) with ESMTP id m7603nW5025177 for ; Tue, 5 Aug 2008 19:03:51 -0500 (CDT) (envelope-from morganw@chemikals.org) Date: Tue, 5 Aug 2008 19:03:49 -0500 (CDT) From: Wes Morgan To: freebsd-fs@freebsd.org Message-ID: User-Agent: Alpine 1.10 (BSF 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII Subject: ZFS Advice X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 06 Aug 2008 00:03:55 -0000 I'm looking for information and advice from those experienced in building storage arrays with good performance. Thus far, I've simply been using a motherboard with a lot of built-in SATA ports. I've concentrated on making most of the investment in high quality storage rather than controllers, cases etc. It's just a 4U chassis (I don't even have a rack for it, too much $$$) with 16 hot-swap bays, for use as a media server. However, I've reached the point where I have a 8-drive raidz2. Any additional storage would need to be another independent raidz2 set, and there are not a lot of inexpensive options for go to 16 ports. So this brings up a few questions: - Has anyone looked at what kind of workloads tend to perform best with prefetch enabled or disabled? - Would I have better performance from a dedicated controller, and would the improvement be worth the cost? As it stands now, heavy read/write activity definitely interferes with both streaming and rtorrent. - The 16-port controllers tend to have a lot of fancy "Intel RAID chips" etc, which is simply a waste of money when using zfs, right? - Is one 16-port controller better than 2 8-port? Assuming two 8-device arrays, which will perform better? - Which brand of controllers are best supported by FreeBSD? I've seen 3Ware, Areca and LSI mentioned, and the prices are all pretty much the same. Can anyone share some of their experiences with these vendors? Thanks, WM