From owner-freebsd-fs@FreeBSD.ORG Fri Jul 23 12:15:30 2010 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 66DAD106567D for ; Fri, 23 Jul 2010 12:15:30 +0000 (UTC) (envelope-from freebsd-fs@m.gmane.org) Received: from lo.gmane.org (lo.gmane.org [80.91.229.12]) by mx1.freebsd.org (Postfix) with ESMTP id 228898FC19 for ; Fri, 23 Jul 2010 12:15:29 +0000 (UTC) Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1OcHA1-0002cB-4R for freebsd-fs@freebsd.org; Fri, 23 Jul 2010 14:15:29 +0200 Received: from lara.cc.fer.hr ([161.53.72.113]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 23 Jul 2010 14:15:29 +0200 Received: from ivoras by lara.cc.fer.hr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 23 Jul 2010 14:15:29 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-fs@freebsd.org From: Ivan Voras Date: Fri, 23 Jul 2010 14:15:44 +0200 Lines: 16 Message-ID: References: <4C496EB0.7050004@fsn.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@dough.gmane.org X-Gmane-NNTP-Posting-Host: lara.cc.fer.hr User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.1.9) Gecko/20100518 Thunderbird/3.0.4 In-Reply-To: <4C496EB0.7050004@fsn.hu> X-Enigmail-Version: 1.0.1 Subject: Re: ZFS makes SSDs faster than memory! 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: Fri, 23 Jul 2010 12:15:30 -0000 On 07/23/10 12:28, Attila Nagy wrote: > Hi, > > I've came across a strange issue. On a file server (ftp/http/rsync) > there is a dual SSD based L2ARC configured for a pool of 24 disks: > fetch -o /dev/null -4 > http://ftp.fsn.hu/pub/CDROM-Images/opensolaris/osol-0906-106a-ai-sparc.iso > /dev/null 100% of 493 MB 11 MBps If I understand your setup and your benchmark correctly, you are saying you have achieved 11 megabytes / s performance out of a volume of 24 RAIDZ2 drives split into two parts (so it's like RAID 60). Doesn't this number seem extremely low to you, considering that (if recent models) each of your drives can probably pull at least 70 MB/s?