From owner-freebsd-stable@FreeBSD.ORG Fri Jan 7 12:33:42 2011 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 608BD106564A for ; Fri, 7 Jan 2011 12:33:42 +0000 (UTC) (envelope-from markiyan.kushnir@gmail.com) Received: from mail-iy0-f182.google.com (mail-iy0-f182.google.com [209.85.210.182]) by mx1.freebsd.org (Postfix) with ESMTP id DA2A18FC17 for ; Fri, 7 Jan 2011 12:33:41 +0000 (UTC) Received: by iyb26 with SMTP id 26so16422756iyb.13 for ; Fri, 07 Jan 2011 04:33:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=T5HGj/dKkLyu5dWWh8qty1d0dvGQdUcvA2LUmQ0lK8g=; b=vAiY1y8zPmACe2LfLgive5oXHI97+UsdwbBUtv4nGvJej373ueNYQ5iwi2vYAKNJkL Re90QOIf35cANzB+rKuBcK648j8eVGSRi6Ty2hfFMdi01/dXIPfAhS093YcFEGPjc+4S o7MIC2UK18IC8XgMw4j1TDw87zE/+sS8a+tv8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=AlwkNH9UuUDw8kV7jMIHjovgRRF376inOqGKjWlcMG7LOQk3Vn4QZcvfUAN6fdrFok M0+ONIhH/w4V4yDhvaxFIQaUy62ZxXx66B3XccEsy9zFAA9lTT0RRcx5P6p5gHGj+sYr 6IwIE2UqPtkCX7iKzQe7XfHPaYEgxD7vX4ois= MIME-Version: 1.0 Received: by 10.231.207.73 with SMTP id fx9mr14702228ibb.137.1294402213832; Fri, 07 Jan 2011 04:10:13 -0800 (PST) Received: by 10.231.147.131 with HTTP; Fri, 7 Jan 2011 04:10:13 -0800 (PST) In-Reply-To: <20110107014249.GA3719@icarus.home.lan> References: <4D1C6F90.3080206@my.gd> <4D21E679.80002@my.gd> <84882169-0461-480F-8B4C-58E794BCC8E6@my.gd> <488AE93A-97B9-4F01-AD0A-0098E4B329C3@my.gd> <20110107014249.GA3719@icarus.home.lan> Date: Fri, 7 Jan 2011 14:10:13 +0200 Message-ID: From: Markiyan Kushnir To: Jeremy Chadwick Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: Chris Forgeron , "freebsd-stable@freebsd.org" , Artem Belevich , Jean-Yves Avenard Subject: Re: ZFS - moving from a zraid1 to zraid2 pool with 1.5tb disks X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 07 Jan 2011 12:33:42 -0000 2011/1/7 Jeremy Chadwick : > On Fri, Jan 07, 2011 at 12:29:17PM +1100, Jean-Yves Avenard wrote: >> On 6 January 2011 22:26, Chris Forgeron wrote: >> > You know, these days I'm not as happy with SSD's for ZIL. I may blog a= bout some of the speed results I've been getting over the last 6mo-1yr that= I've been running them with ZFS. I think people should be using hardware R= AM drives. You can get old Gigabyte i-RAM drives with 4 gig of memory for t= he cost of a 60 gig SSD, and it will trounce the SSD for speed. >> > >> > I'd put your SSD to L2ARC (cache). >> >> Where do you find those though. >> >> I've looked and looked and all references I could find was that >> battery-powered RAM card that Sun used in their test setup, but it's >> not publicly available.. > > DDRdrive: > =A0http://www.ddrdrive.com/ > =A0http://www.engadget.com/2009/05/05/ddrdrives-ram-based-ssd-is-snappy-c= ostly/ > > ACard ANS-9010: > =A0http://techreport.com/articles.x/16255 > > GC-RAMDISK (i-RAM) products: > =A0http://us.test.giga-byte.com/Products/Storage/Default.aspx > > Be aware these products are absurdly expensive for what they offer (the > cost isn't justified), not to mention in some cases a bottleneck is > imposed by use of a SATA-150 interface. =A0I'm also not sure if all of > them offer BBU capability. > > In some respects you might be better off just buying more RAM for your > system and making md(4) memory disks that are used by L2ARC (cache). > I've mentioned this in the past (specifically "back in the days" when > the ARC piece of ZFS on FreeBSD was causing havok, and asked if one > could work around the complexity by using L2ARC with md(4) drives > instead). > Once you have got extra RAM, why not just reserve it directly to ARC (via vm.kmem_size[_max] and vfs.zfs.arc_max)? Markiyan. > I tried this, but couldn't get rc.d/mdconfig2 to do what I wanted on > startup WRT the aforementioned. > > -- > | Jeremy Chadwick =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0= =A0 =A0 =A0 jdc@parodius.com | > | Parodius Networking =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 http://= www.parodius.com/ | > | UNIX Systems Administrator =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0Mountain = View, CA, USA | > | Making life hard for others since 1977. =A0 =A0 =A0 =A0 =A0 =A0 =A0 PGP= 4BD6C0CB | > > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" >