From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756674AbZDDTM4 (ORCPT ); Sat, 4 Apr 2009 15:12:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754005AbZDDTMo (ORCPT ); Sat, 4 Apr 2009 15:12:44 -0400 Received: from mx03.syneticon.net ([78.111.66.105]:60646 "EHLO mx03.syneticon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751588AbZDDTMm (ORCPT ); Sat, 4 Apr 2009 15:12:42 -0400 Message-ID: <49D7B122.50103@wpkg.org> Date: Sat, 04 Apr 2009 21:12:34 +0200 From: Tomasz Chmielewski User-Agent: Thunderbird 2.0.0.21 (X11/20090319) MIME-Version: 1.0 To: Vladislav Bolkhovitin CC: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, iscsitarget-devel@lists.sourceforge.net, James Bottomley , scst-devel , stgt@vger.kernel.org Subject: Re: [Scst-devel] [ANNOUNCE]: Comparison of features sets between different SCSI targets (SCST, STGT, IET, LIO) References: <49D7AD54.4060408@vlnb.net> In-Reply-To: <49D7AD54.4060408@vlnb.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Vladislav Bolkhovitin schrieb: > Hi All, > > I set up http://scst.sourceforge.net/comparison.html page, which > compares features of existing SCSI target subsystems for Linux. The > comparison includes SCST, STGT, IET and LIO. > > I might be not fully correct somewhere, so, if you don't agree with me > about some item(s) in the comparison table, please let me know and I > will fix that. Performance is a bit debatable. I made some simple SCST and STGT tests last week, there were some where SCST won, there were some where STGT won. What was surprising to me, although STGT has a bigger CPU impact than SCST, STGT was faster when reading from an encrypted (dm-crypt) volume, on a system where the CPU is the bottleneck (it can't decrypt as fast as HDD can deliver data). STGT was much slower when reading from a non-encrypted volume, when target had "blockdev --setra 16384 ..." for a given target. On the other hand, STGT was faster than SCST with default blockdev readahead settings (256). If anyone's interested, I can show results in a readable form on Monday (right now, I have only raw data which is pretty long and would be hard to compare). -- Tomasz Chmielewski http://wpkg.org