From owner-freebsd-current@FreeBSD.ORG Sat Dec 15 18:15:42 2007 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9236B16A418 for ; Sat, 15 Dec 2007 18:15:42 +0000 (UTC) (envelope-from bofh@terranova.net) Received: from tog.net (tog.net [216.89.226.5]) by mx1.freebsd.org (Postfix) with ESMTP id 66EED13C447 for ; Sat, 15 Dec 2007 18:15:42 +0000 (UTC) (envelope-from bofh@terranova.net) Received: from [216.89.228.170] (host-216-89-228-170.wireless.terranova.net [216.89.228.170]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by tog.net (Postfix) with ESMTP id A914429B5FB for ; Sat, 15 Dec 2007 13:15:41 -0500 (EST) Message-ID: <476419CD.9070401@terranova.net> Date: Sat, 15 Dec 2007 13:15:41 -0500 From: Travis Mikalson Organization: TerraNovaNet Internet Services User-Agent: Thunderbird 1.5.0.13 (Windows/20070809) MIME-Version: 1.0 To: freebsd-current@freebsd.org References: <47606C09.2070209@isc.org> <47609F0A.7010805@clearchain.com> <47609FE3.8040606@barafranca.com> <4760B444.1080604@clearchain.com> <06CAC7FC-DB58-441D-A6E0-76D1D8133393@tamu.edu> <86ir31xwlu.fsf@ds4.des.no> <476343B4.8080208@FreeBSD.org> <86tzmk54tt.fsf@ds4.des.no> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: ZFS melting under postgres... X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 15 Dec 2007 18:15:42 -0000 Ivan Voras wrote: > Dag-Erling Smørgrav wrote: >> Ivan Voras writes: >>> Maxim Sobolev wrote: >>>> That's no longer true. You can't get more than 5-10MB/s from >>>> seek-intensive RAID0 with two 15K drives, while 20-30MB/s is not a >>>> problem for the comparable priced/sized SSD drive. >>> Can you point me at a vendor with SSDs of such characteristics? >> Kingston CF Elite, 20 / 25 MBps write / read >> Kingston CF Ultimate, 40 / 45 MBps write / read >> >> SanDisk Extreme III CF, 20 MBps >> SanDisk Extreme IV CF, 45 MBps >> >> Sony CF 300X, 45 MBps >> >> These are just a few of those available from my regular supplier. > > These are all "normal" CompactFlash cards, for which the widely > available size seems to be 16 GB max, right? I was thinking about > something more like this: > http://gizmodo.com/gadgets/peripherals/adatas-128gb-solid-state-drive-sees-the-light-of-day-231693.php > or this: http://www.mtron.net/English/Product/pc_msd1000.asp > > Did you (or anyone) deploy CF drives for production servers? If you're using compact flash for something that's constantly updated like a ZIL, wouldn't your CF card die real quick? I've deployed CF in production, but as a read-only medium with occasional writes only for configuration updates. From what I understand the specialized expensive solid-state drives that you guys are discussing are better designed for this type of write duty whereas CF would probably not last very long. Since a ZIL is not really seek-intensive, why not just offload it to its own standard hard disk that has its write caching and all other similar data-corrupting technologies disabled?