From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian King Subject: Re: [Bug 16070] New: Fail to issue Start/Stop Unit Date: Fri, 28 May 2010 10:35:22 -0500 Message-ID: <4BFFE2BA.6030307@linux.vnet.ibm.com> References: <4BFFDF2A.1060404@interlog.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from e5.ny.us.ibm.com ([32.97.182.145]:46972 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750929Ab0E1Pfb (ORCPT ); Fri, 28 May 2010 11:35:31 -0400 Received: from d01relay03.pok.ibm.com (d01relay03.pok.ibm.com [9.56.227.235]) by e5.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id o4SFIx6O027769 for ; Fri, 28 May 2010 11:18:59 -0400 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay03.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o4SFZNit067446 for ; Fri, 28 May 2010 11:35:23 -0400 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id o4SFZNpE019222 for ; Fri, 28 May 2010 11:35:23 -0400 In-Reply-To: <4BFFDF2A.1060404@interlog.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: dgilbert@interlog.com Cc: bugzilla-daemon@bugzilla.kernel.org, linux-scsi@vger.kernel.org On 05/28/2010 10:20 AM, Douglas Gilbert wrote: > On 10-05-28 10:55 AM, bugzilla-daemon@bugzilla.kernel.org wrote: >> https://bugzilla.kernel.org/show_bug.cgi?id=16070 >> >> Summary: Fail to issue Start/Stop Unit >> Product: IO/Storage >> Version: 2.5 >> Kernel Version: 2.6.34-rc5 >> Platform: All >> OS/Version: Linux >> Tree: Mainline >> Status: NEW >> Severity: normal >> Priority: P1 >> Component: SCSI >> AssignedTo: linux-scsi@vger.kernel.org >> ReportedBy: ian@beware.dropbear.id.au >> Regression: No >> >> >> I am attempting to save power by spinning down idle scsi disks. These >> are old >> fashioned parallel (U320) disks on a SCSI storage controller: LSI Logic / >> Symbios Logic 53c1030 PCI-X Fusion-MPT Dual Ultra320 SCSI (rev 07). >> >> I do: >> >> sg_start --stop /dev/sde >> echo 0xfffffff> /sys/module/scsi_mod/parameters/scsi_logging_level >> dd if=/dev/sde of=/dev/null count=1 >> sleep 10 >> echo 0> /sys/module/scsi_mod/parameters/scsi_logging_level >> >> I get: >> dd: reading `/dev/sde': Input/output error >> 0+0 records in >> 0+0 records out >> 0 bytes (0 B) copied, 0.00536828 s, 0.0 kB/s >> >> If I manually spin up the disk with sg_start --start /dev/sde, then >> things work >> again as expected. > > >> >> After getting: "Add. Sense: Logical unit not ready, initializing command >> required" I would expect a Start/Stop unit command, but it appears >> that none is >> ever issued. > > There is a different design philosophy between SCSI and > ATA disks (and has been for a very long time) reflecting > their different markets. When a SCSI disk is spun down, then > it will return errors on any command trying to do IO > until a SCSI START STOP UNIT command (start) is sent and then > time is allowed for the disk to spin up. > > What you report as a bug is the long standing behaviour of > SCSI disks which Linux has not tried to modify. If you set the allow_restart sysfs parameter on the disk, it should automatically spin up the disk when scsi eh sees that sense data. Thanks, Brian -- Brian King Linux on Power Virtualization IBM Linux Technology Center