Date: Wed, 15 Jul 2009 11:53:39 +0800 From: Jiansong Liu <jiansong.liu@gmail.com> To: Ivan Voras <ivoras@freebsd.org> Cc: freebsd-scsi@freebsd.org Subject: Re: iscsi_initiator 2.2.2 slow to write and read Message-ID: <7f834c1c0907142053oc0271c6kbf85872a92f6ebbb@mail.gmail.com> In-Reply-To: <h3evt6$sd2$1@ger.gmane.org> References: <7f834c1c0907070405mdab72u3223d90b84b2a201@mail.gmail.com> <20090707173629.GA33007@in-addr.com> <7f834c1c0907102141n5d55f786keb55f44126cd94c2@mail.gmail.com> <h3evt6$sd2$1@ger.gmane.org>
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On Mon, Jul 13, 2009 at 5:48 PM, Ivan Voras <ivoras@freebsd.org> wrote: > Jiansong Liu wrote: > >> On Wed, Jul 8, 2009 at 1:36 AM, Gary Palmer <gpalmer@freebsd.org> 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
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