From mboxrd@z Thu Jan 1 00:00:00 1970 From: Douglas Gilbert Subject: Re: SCSI target and IO-throttling Date: Tue, 14 Mar 2006 15:54:32 -0500 Message-ID: <44172D88.6070201@torque.net> References: <440EF9AC.7070903@vlnb.net> <440F1920.1050608@vlnb.net> <43998989-7BD3-4F3F-A10A-17385D63411E@egenera.com> <441075D4.6010109@vlnb.net> <80454C34-75B9-409B-A454-B8AB0DB1AF4D@egenera.com> <4411C99C.9040200@vlnb.net> Reply-To: dougg@torque.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from canuck.infradead.org ([205.233.218.70]:49289 "EHLO canuck.infradead.org") by vger.kernel.org with ESMTP id S932132AbWCNU5Z (ORCPT ); Tue, 14 Mar 2006 15:57:25 -0500 In-Reply-To: <4411C99C.9040200@vlnb.net> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Vladislav Bolkhovitin Cc: Steve Byan , Bryan Henderson , linux-scsi@vger.kernel.org Vladislav Bolkhovitin wrote: > Steve Byan wrote: > BTW, do you have any statistic how many modern SCSI disks support those > features (ORDERED, ACA, UA_INTLCK_CTL, etc)? Few years ago none of > available for us SCSI hardware, including tape libraries, supported ACA. > It was not very modern for that time, though Vlad, Here is part of the control mode page from a recent SCSI disk (Cheetah 15k.4) : # sdparm -p co /dev/sdb -ll /dev/sdb: SEAGATE ST336754SS 0003 Direct access device specific parameters: WP=0 DPOFUA=1 Control mode page [PS=1]: TST 0 [cha: n, def: 0, sav: 0] Task set type 0: lu maintains one task set for all I_T nexuses 1: lu maintains separate task sets for each I_T nexus TMF_ONLY 0 [cha: n, def: 0, sav: 0] Task management functions only D_SENSE 0 [cha: n, def: 0, sav: 0] Descriptor format sense data GLTSD 0 [cha: y, def: 1, sav: 0] Global logging target save disable RLEC 0 [cha: y, def: 0, sav: 0] Report log exception condition QAM 0 [cha: y, def: 0, sav: 0] Queue algorithm modifier 0: restricted re-ordering; 1: unrestricted QERR 0 [cha: n, def: 0, sav: 0] Queue error management 0: only affected task gets CC; 1: affected tasks aborted 3: affected tasks aborted on same I_T nexus RAC 0 [cha: n, def: 0, sav: 0] Report a check UA_INTLCK 0 [cha: n, def: 0, sav: 0] Unit attention interlocks control 0: unit attention cleared with check condition status 2: unit attention not cleared with check condition status 3: as 2 plus ua on busy, task set full or reservation conflict SWP 0 [cha: n, def: 0, sav: 0] Software write protect ATO 0 [cha: n, def: 0, sav: 0] Application tag owner TAS 0 [cha: n, def: 0, sav: 0] Task aborted status 0: tasks aborted without response to app client 1: any other I_T nexuses receive task aborted So it doesn't support UA_INTLCK ("cha: n" implies the user cannot change that value). QAM can be changed to allow unrestricted re-ordering (of task with the SIMPLE task attribute). The NormACA bit in the standard INQUIRY response is 0 so it doesn't support ACA either. Doug Gilbert