From owner-freebsd-scsi@FreeBSD.ORG Wed Jul 15 03:53:59 2009 Return-Path: Delivered-To: freebsd-scsi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D1450106566B for ; Wed, 15 Jul 2009 03:53:59 +0000 (UTC) (envelope-from jiansong.liu@gmail.com) Received: from wa-out-1112.google.com (wa-out-1112.google.com [209.85.146.182]) by mx1.freebsd.org (Postfix) with ESMTP id 9BB818FC0A for ; Wed, 15 Jul 2009 03:53:59 +0000 (UTC) (envelope-from jiansong.liu@gmail.com) Received: by wa-out-1112.google.com with SMTP id m38so857544waf.27 for ; Tue, 14 Jul 2009 20:53:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :from:date:message-id:subject:to:cc:content-type; bh=u8ODvID6feUAuEdiI8+WfZtATa3Tbn0mXAQZkfTcpwU=; b=ME0FqfNURW+sucFccOgjzI6ME12DTO8sA/QcIIxsMYu9F9S15iPWIszYj1JembyNjt GT16sJKbobA8xIQQpxvxao/nNnboprfUq13G4i9U8Nyo2zCE9MW0VoCzR5jh4XaRiwOZ hRIysCwvdsG8IzKxI+bLtcs1KYfihMXGhM7Ro= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; b=UbWK8WeSTpLZGQSVLNI6CmeMDHJl4H3zFuqsn36axAnjyLrKKqCS6jUCOop91KWO0l lIQLApekHvA4zSawYbEP79MQJVfG4PVWA5hI5kbZOaiE2nDZJbMN/y1DAicfQlXeJ5ZK tBaJEI91bQDleUfVSS3k8CSldi5nZQUF6gBXQ= MIME-Version: 1.0 Received: by 10.114.185.8 with SMTP id i8mr11856385waf.85.1247630039220; Tue, 14 Jul 2009 20:53:59 -0700 (PDT) In-Reply-To: References: <7f834c1c0907070405mdab72u3223d90b84b2a201@mail.gmail.com> <20090707173629.GA33007@in-addr.com> <7f834c1c0907102141n5d55f786keb55f44126cd94c2@mail.gmail.com> From: Jiansong Liu Date: Wed, 15 Jul 2009 11:53:39 +0800 Message-ID: <7f834c1c0907142053oc0271c6kbf85872a92f6ebbb@mail.gmail.com> To: Ivan Voras Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-scsi@freebsd.org Subject: Re: iscsi_initiator 2.2.2 slow to write and read X-BeenThere: freebsd-scsi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SCSI subsystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 15 Jul 2009 03:54:00 -0000 On Mon, Jul 13, 2009 at 5:48 PM, Ivan Voras wrote: > Jiansong Liu wrote: > >> On Wed, Jul 8, 2009 at 1:36 AM, Gary Palmer wrote: >> >> On Tue, Jul 07, 2009 at 07:05:03PM +0800, Jiansong Liu wrote: >>> >>>> Hello All, >>>> . >>> >>> . >>>> >>>> =iqn.1984-05.com.dell:powervault.md3000i.60024e80004e71a9000000004a011120 >>> >>> TargetAddress =192.168.4.182:3260,1 >>>> tags =4 >>>> } >>>> >>> I'm no expert, but if that "tags" line refers to SCSI tags then that >>> number is too small. Try increasing it and see if that helps to >>> address the problem. >>> >>> Regards, >>> >>> Gary >>> >>> >> Hi Gary, >> >> Thanks for the advice, I have tried set tags to 32 and 64, >> but it could not get more performance on IO (90MB write and 56MB read). >> I think the writing is good enough for my application, but the reading >> still >> is a problem. >> >> # dd if=/home/mogdata/test.foo of=/dev/null >> 2048000+0 records in >> 2048000+0 records out >> 1048576000 bytes transferred in 17.670549 secs (59340318 bytes/sec) >> > > Are you really reading sector by sector? Try adding bs=1m to the dd line. > > There is something else you can try to increase sequential reading, if > that's what you're interested in: increase the vfs.read_max sysctl to 32 or > 64. > > On the other hand, it will do nothing to improve, and may harm random read > performance. Test with your actual application before drawing conclusions. > Hi Ivan,It got 8MB/s better after adding bs=1m to the dd command. Thanks for your notice, random read is more important to my application, it is a image storage which stores pictures between 10KB~5MB, sequential reading performance is not important. Thanks all who kindly gave advice to me. Best regards, Liu Jiansong