From 074165761ca1d0abd81fc71353748db66e60a493 Mon Sep 17 00:00:00 2001 From: Douglas Gilbert Date: Sat, 15 Aug 2009 18:46:28 +0000 Subject: sg_raw binary reads on Windows; move sas_disk_blink to sdparm git-svn-id: https://svn.bingwo.ca/repos/sg3_utils/trunk@285 6180dd3e-e324-4e3e-922d-17de1ae2f315 --- doc/sg_reset.8 | 42 +++++++++++++++++++++++------------------- 1 file changed, 23 insertions(+), 19 deletions(-) (limited to 'doc/sg_reset.8') diff --git a/doc/sg_reset.8 b/doc/sg_reset.8 index f24aff05..d6245762 100644 --- a/doc/sg_reset.8 +++ b/doc/sg_reset.8 @@ -1,4 +1,4 @@ -.TH SG_RESET "8" "June 2009" "sg3_utils\-1.28" SG3_UTILS +.TH SG_RESET "8" "July 2009" "sg3_utils\-1.28" SG3_UTILS .SH NAME sg_reset \- sends SCSI device, target, bus or host reset; or checks reset state .SH SYNOPSIS @@ -44,7 +44,7 @@ attempt a host adapter reset. This would normally be tried if both device reset (i.e. option \fI\-d\fR) and bus reset (i.e. option \fI\-b\fR) were not successful. .TP -\fB\-d\fR +\fB\-t\fR attempt a SCSI target reset. This assumes the linux scsi mid level error handler is not already in the process of resetting the target that contains the given \fIDEVICE\fR. @@ -52,7 +52,7 @@ contains the given \fIDEVICE\fR. \fB\-V\fR prints the version string then exits. .SH NOTES -The error recovery code within the linux kernel when faced with SCSI commands +The error recovery code within the linux kernel when faced with a SCSI command timing out and no response from the device (LU), first tries a device reset and if that is not successful tries a target reset. If that is not successful it tries a bus reset. If that is not successful it tries a host reset. Users @@ -62,26 +62,30 @@ order is also recommended (i.e. first start with the smallest hammer). The above is a generalization and exact details will vary depending on the transport and the low level driver concerned. .PP -SAM\-4 defines a hard reset (which includes a device power on and a transport -reset), a logical unit reset and a I_T nexus reset. A LU reset and an I_T -nexus reset can be requested via task management function (and support for LU -reset is mandatory). In Linux the SCSI subsystem leaves it up to the low level -drivers as to whether a "device reset" is only for the addressed LU or all -the LUs in the device that contains the addressed LU (i.e. a target reset). -The additional of the target reset (i.e. option \fI\-t\fR) should give more -control in this area. The "bus reset" is a transport reset and may be a dummy -operation, depending on the transport. A "host reset" attempts to -re\-initialize the HBA that the request passes through en route to the -\fIDEVICE\fR. Obviously a "host reset" and a "bus reset" can cause collateral -damage. +SAM\-4 defines a hard reset, a logical unit reset and a I_T nexus reset. A +hard reset is defined to be a power on condition, a microcode change or a +transport reset event. A LU reset and an I_T nexus reset can be requested +via task management function (and support for LU reset is mandatory). In +Linux the SCSI subsystem leaves it up to the low level drivers as to whether +a "device reset" is only for the addressed LU or all the LUs in the device +that contains the addressed LU (i.e. a target reset). The additional of the +target reset (i.e. option \fI\-t\fR) should give more control in this area. +The "bus reset" is a transport reset and may be a dummy operation, depending +on the transport. A "host reset" attempts to re\-initialize the HBA that the +request passes through en route to the \fIDEVICE\fR. Note that a "host reset" +and a "bus reset" may cause collateral damage. +.PP +This utility does not allow individual SCSI commands (or tasks as they are +called in SAM\-4) to be aborted. SAM\-4 defines ABORT TASK and ABORT TASK +SET task management functions for that. .PP -This utility does not allow individual SCSI commands (or tasks -as they are called in SAM\-4) to be aborted. SAM\-4 defines -ABORT TASK and ABORT TASK SET task management functions for that. +Prior to SAM\-3 there was a TARGET RESET task management function. Several +transports still support that function and many associated linux low level +drivers map the \fI\-t\fR option to it. .SH AUTHORS Written by Douglas Gilbert. .SH COPYRIGHT -Copyright \(co 1999\-2006 Douglas Gilbert +Copyright \(co 1999\-2009 Douglas Gilbert .br This software is distributed under the GPL version 2. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. -- cgit v1.2.3