Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933829AbZDAUOm (ORCPT ); Wed, 1 Apr 2009 16:14:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756653AbZDAUO3 (ORCPT ); Wed, 1 Apr 2009 16:14:29 -0400 Received: from mail-bw0-f169.google.com ([209.85.218.169]:57012 "EHLO mail-bw0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756434AbZDAUO2 convert rfc822-to-8bit (ORCPT ); Wed, 1 Apr 2009 16:14:28 -0400 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=tRorurK948ail6tkXP/FpGs2E1qKvIxHmNiGpF1U22ueOqNnDRKSc2C+rmJfBv9O6E f/UgH/M10xKBE9+4dYOf6cOlkEfe91vIFy7y6ow5TUqE7b+t+4xSYl7FzvjQlq6Dewk5 Y227WlnbB/peQYwMNpSihYqPOgKTr56NRYMbY= MIME-Version: 1.0 In-Reply-To: <49D10256.8030307@vlnb.net> References: <49D10256.8030307@vlnb.net> Date: Wed, 1 Apr 2009 22:14:24 +0200 Message-ID: Subject: Re: ISCSI-SCST performance (with also IET and STGT data) From: Bart Van Assche To: Vladislav Bolkhovitin Cc: scst-devel , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, iscsitarget-devel@lists.sourceforge.net, stgt@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1665 Lines: 41 On Mon, Mar 30, 2009 at 7:33 PM, Vladislav Bolkhovitin wrote: ================================================================== > > I. SEQUENTIAL ACCESS OVER SINGLE LINE > > 1. # dd if=/dev/sdX of=/dev/null bs=512K count=2000 > > ? ? ? ? ? ? ? ? ? ? ? ?ISCSI-SCST ? ? ?IET ? ? ? ? ? ? STGT > NULLIO: ? ? ? ? ? ? ? ? 106 ? ? ? ? ? ? 105 ? ? ? ? ? ? 103 > FILEIO/CFQ: ? ? ? ? ? ? 82 ? ? ? ? ? ? ?57 ? ? ? ? ? ? ?55 > FILEIO/deadline ? ? ? ? 69 ? ? ? ? ? ? ?69 ? ? ? ? ? ? ?67 > BLOCKIO/CFQ ? ? ? ? ? ? 81 ? ? ? ? ? ? ?28 ? ? ? ? ? ? ?- > BLOCKIO/deadline ? ? ? ?80 ? ? ? ? ? ? ?66 ? ? ? ? ? ? ?- I have repeated some of these performance tests for iSCSI over IPoIB (two DDR PCIe 1.0 ConnectX HCA's connected back to back). The results for the buffered I/O test with a block size of 512K (initiator) against a file of 1GB residing on a tmpfs filesystem on the target are as follows: write-test: iSCSI-SCST 243 MB/s; IET 192 MB/s. read-test: iSCSI-SCST 291 MB/s; IET 223 MB/s. And for a block size of 4 KB: write-test: iSCSI-SCST 43 MB/s; IET 42 MB/s. read-test: iSCSI-SCST 288 MB/s; IET 221 MB/s. Or: depending on the test scenario, SCST transfers data between 2% and 30% faster via the iSCSI protocol over this network. Something that is not relevant for this comparison, but interesting to know: with the SRP implementation in SCST the maximal read throughput is 1290 MB/s on the same setup. Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/