From owner-freebsd-performance@FreeBSD.ORG Tue Sep 28 12:44:51 2010 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5F725106566B for ; Tue, 28 Sep 2010 12:44:51 +0000 (UTC) (envelope-from ssanders@softhammer.net) Received: from oproxy1-pub.bluehost.com (oproxy1-pub.bluehost.com [66.147.249.253]) by mx1.freebsd.org (Postfix) with SMTP id 2DB668FC08 for ; Tue, 28 Sep 2010 12:44:51 +0000 (UTC) Received: (qmail 1399 invoked by uid 0); 28 Sep 2010 11:46:05 -0000 Received: from unknown (HELO host358.hostmonster.com) (66.147.240.158) by oproxy1.bluehost.com.bluehost.com with SMTP; 28 Sep 2010 11:46:04 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=default; d=softhammer.net; h=Received:Message-ID:Date:From:User-Agent:MIME-Version:To:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding:X-Identified-User; b=vdP1DuT9shBPgl8VuNS6KSOVHeprAgRF35LFTVsNIAV3jgWox2iYlteR5PkBmiuGxkmtj944R2xBpQQn+vYqrNCIHyRVTAxrwBCPoOAXQp3+ZooM5LFSkXUp6ljqftRk; Received: from pool-74-96-233-244.washdc.fios.verizon.net ([74.96.233.244] helo=[192.168.1.54]) by host358.hostmonster.com with esmtpa (Exim 4.69) (envelope-from ) id 1P0ZY6-0005v6-7z for freebsd-performance@freebsd.org; Tue, 28 Sep 2010 06:44:46 -0600 Message-ID: <4CA1E33C.70200@softhammer.net> Date: Tue, 28 Sep 2010 08:44:44 -0400 From: Stephen Sanders User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc13 Thunderbird/3.1.4 MIME-Version: 1.0 To: freebsd-performance@freebsd.org References: <4CA14009.4050906@softhammer.net> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Identified-User: {2492:host358.hostmonster.com:softhamm:softhammer.net} {sentby:smtp auth 74.96.233.244 authed with ssanders@softhammer.net} Subject: Re: gstripe small transaction size X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Sep 2010 12:44:51 -0000 Increasing MAXPHYS and turning up the stripe size won't have the effect I'm looking for ? I see where MAXPHYS is now a kernel configuration parameter in FreeBSD 8.1. Thanks. On 09/28/2010 06:44 AM, Ivan Voras wrote: > On 09/28/10 03:08, Stephen Sanders wrote: >> I'm trying a disk throughput experiment where in two 3ware raid 6's are >> being put into a g_strip raid 0. >> >> The raid 6's are using 8 7200RPM disks. The disk transfer rate is >> ~80MB/s. Using a load generation tool that is using O_DIRECT for I/O, >> I've generated the following short output from iostat. Needless to say, >> the write performance is a lot less than I'm expecting. >> >> We've modified the kernel such that our KB/t figure is closer to 512KB/t >> per disk when measured without the g_strip. With g_strip turned on, the >> KB/t number is more like 60KB/t. >> >> The question is how do I get g_stripe to write larger transactions to >> the disk ? >> >> gstripe label -v -s 131072 roadkill /dev/da0 /dev/da2 > > No pratical way. You have a gstripe array of two drives and with > MAXPHYS of 128 KiB each would in fact see at most 64 KiB transactions. > It gets worse when you add drives. > >> newfs /dev/stripe/roadkill > > Depending on what you are doing, adding "-U" would help you here. > > > _______________________________________________ > freebsd-performance@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-performance > To unsubscribe, send any mail to > "freebsd-performance-unsubscribe@freebsd.org" >