From owner-freebsd-hardware@FreeBSD.ORG Wed Aug 29 05:49:41 2012 Return-Path: Delivered-To: freebsd-hardware@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 75AED106566B for ; Wed, 29 Aug 2012 05:49:41 +0000 (UTC) (envelope-from ndenev@gmail.com) Received: from mail-wg0-f50.google.com (mail-wg0-f50.google.com [74.125.82.50]) by mx1.freebsd.org (Postfix) with ESMTP id EFE628FC18 for ; Wed, 29 Aug 2012 05:49:40 +0000 (UTC) Received: by wgbds11 with SMTP id ds11so127282wgb.31 for ; Tue, 28 Aug 2012 22:49:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:mime-version:content-type:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to:x-mailer; bh=IOvCrMlancS57bdRO8Xjk/Z9ApxP7tHqZpspcpzT9fw=; b=tky5upbib3HAYT93ZI6mEPWTOXZJErcT6v+LLOoCE9kdc286ESkK0G4BvzGYbBNXyV HXyleFhRlXbrhLxQNOi4yx1nhxkZJ6116vGuPgzuriXz28kSOMW5v6q3o2qmMpTg409t Ca96NE6nMnJdzj7RSeIMioROKDyhTHw5KXPZzIP0I3rbiBROooMH95zfsnNjkbPGZdaa CzltoQIiDBKzcZupWcSi8R/TTsWijxMbxA4HQdHmBUfNV5+xWwYj4oW9TaOVPwiUqDXc xu9WuLHlOMSbVtyLwpvSEORdRxHuzN0mcB4ucVsIk3aFaqxRjdd1TLLqUUdq7m6IM5ey 1Ysw== Received: by 10.180.97.135 with SMTP id ea7mr37750825wib.11.1346219379663; Tue, 28 Aug 2012 22:49:39 -0700 (PDT) Received: from [10.0.0.86] ([93.152.184.10]) by mx.google.com with ESMTPS id l6sm8541707wiz.4.2012.08.28.22.49.38 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 28 Aug 2012 22:49:38 -0700 (PDT) Mime-Version: 1.0 (Mac OS X Mail 6.0 \(1486\)) Content-Type: text/plain; charset=us-ascii From: Nikolay Denev In-Reply-To: <3F6C1EB2-1EC4-4863-A5BF-093649D9D61C@mosaicarchive.com> Date: Wed, 29 Aug 2012 08:49:37 +0300 Content-Transfer-Encoding: quoted-printable Message-Id: <4D5E46B8-B1C5-4131-BEB3-673769B844E7@gmail.com> References: <503D3026.6010901@ixsystems.com> <503D4F48.9020108@tcbug.org> <3F6C1EB2-1EC4-4863-A5BF-093649D9D61C@mosaicarchive.com> To: Andrew Young X-Mailer: Apple Mail (2.1486) Cc: Josh Paetzel , "freebsd-hardware@freebsd.org" Subject: Re: Support for Fusion IO drives? X-BeenThere: freebsd-hardware@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: General discussion of FreeBSD hardware List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Aug 2012 05:49:41 -0000 Fron the zpool man page: By default, the intent log is allocated from blocks within the main = pool. However, it might be possible to get better performance using = separate intent log devices such as NVRAM or a dedicated disk. I was also contemplating the idea of a fast SSD on PCIe as a ZIL and = L2ARC. And given the fact that the SSD will not suffer from the different types = and locations of IO requests, maybe it makes sense to go with a big SSD, and partition it for a small = ZIL partition, and the rest for L2ARC. Anyone tried that? Regards, Nikolay On Aug 29, 2012, at 2:47 AM, Andrew Young = wrote: > Thanks for the great feedback Josh! The optimum size for an ssd zil = device was still an open question for us. I'm really glad to hear that = they don't need to be that big. >=20 > What does zfs do with the zil if there is no dedicated zil device? Our = servers consist of a small sata drive that holds the OS and a boatload = of larger drives on a sas bus. What I'm wondering is if I simply replace = the OS disk with an ssd will I get the same performance boost as if I = added a dedicated ssd zil?=20 >=20 > Thanks! > Andy >=20 > On Aug 28, 2012, at 7:07 PM, Josh Paetzel wrote: >=20 >>>> -------- Original Message -------- >>>> Subject: Support for Fusion IO drives? >>>> Date: Tue, 28 Aug 2012 16:46:00 -0400 >>>> From: Andy Young >>>> To: freebsd-hardware@freebsd.org >>>>=20 >>>>=20 >>>> We are investigating adding SSDs as ZIL devices to boost our ZFS = write >>>> performance. I read an article a while ago about iX Systems teaming = up >>>> with >>>> Fusion IO to integrate their hardware with FreeBSD. Does anyone = know >>>> anything about supported drivers for Fusion IO's iodrives? >>>>=20 >>>> Thanks! >>>>=20 >>>> Andy >>>> _______________________________________________ >>>> freebsd-hardware@freebsd.org mailing list >>>> http://lists.freebsd.org/mailman/listinfo/freebsd-hardware >>>> To unsubscribe, send any mail to >>>> "freebsd-hardware-unsubscribe@freebsd.org" >>>>=20 >>>>=20 >>>>=20 >>>>=20 >>=20 >> I'll put on my iXsystems hat here, as well as my fast storage, ZFS = and >> Fusion-I/O hat. >>=20 >> The ZFS filesystem supports dedicated ZIL devices, which can = accelerate >> certain types of write requests, notably related to fsync. The = VMWare >> NFS client issues a sync with every write, and most databases do as >> well. In those types of environments having a fast dedicated ZIL = device >> is almost essential. In other environments the benefits of a = dedicated >> ZIL range from non-existent to substantial. >>=20 >> A good dedicated ZIL device is all about latency. It doesn't need to = be >> large, in fact it will only ever handle 10 seconds of writes, so 10x >> network bandwidth is worst case. (In most environments this means = 20GB >> is larger than needed). >>=20 >> Fusion-I/O cards are far too large to be cost effective ZIL devices. >> Even though they do rock at I/O latency, the really fast ones are = also >> fairly large, so the $/GB on them isn't so attractive. There are = better >> options for ZIL devices. >>=20 >> Another consideration is the Fusion-I/O driver is fairly memory = hungry, >> which competes with memory ZFS wants to use for read caching. >>=20 >> Now as an L2ARC device, that's a whole different can of worms. >>=20 >> Command line used: iozone -r 4k -s 96g -i 0 -i 1 -i 2 -t 8 >> Parent sees throughput for 8 readers =3D 1712399.95 KB/sec >> L2 ARC Breakdown: 197.45m >> Hit Ratio: 98.61% 194.71m >> L2 ARC Size: (Adaptive) 771.13 GiB >> ARC Efficiency: 683.40m >> Actual Hit Ratio: 71.09% 485.82m >>=20 >> ~ 800GB test data, all served from cache. >>=20 >> If you are considering Fusion-I/O, the FreeBSD driver is generally = not >> released to the general public by Fusion-I/O, but can be obtained = from >> various partners. (I believe iXsystems is the only FreeBSD friendly >> fusion-i/o partner but could be wrong about that) >>=20 >>=20 >> --=20 >> Thanks, >>=20 >> Josh Paetzel >>=20 > _______________________________________________ > freebsd-hardware@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hardware > To unsubscribe, send any mail to = "freebsd-hardware-unsubscribe@freebsd.org"