If a result is generated it is sent to standard output, and the program
exits with a zero value. If no identifier is output, the program exits
-with a non-zero value.
+with a non\-zero value.
\fBscsi_id\fP is primarily for use by other utilities such as \fBudev\fP
that require a unique SCSI identifier.
-By default all devices are assume black listed, the \fB-g\fP option must
+By default all devices are assume black listed, the \fB\-g\fP option must
be specified on the command line or in the config file for any useful
behaviour.
.fi
.P
-
.SH OPTIONS
.TP
+.BI subsystem
+Deprecated method: when called with only a single argument without a
+leading \-, runs in a hotplug mode, and expects the environment variable
+DEVPATH to specify the corresponding sysfs device. See section below on
+usage with \fBudev\fP.
+.TP
+.BI \-a
+Always print information (model, vendor strings) about the device even
+if it does not support VPD pages.
+.TP
.BI \-b
-The default behaviour - treat the device as black listed, and do nothing
-unless a white listed device is found in the scsi_id config-file.
+The default behaviour \- treat the device as black listed, and do nothing
+unless a white listed device is found in the scsi_id config\-file.
.TP
.BI \-d "\| device\^"
Instead
of determining and creating a device node based on a sysfs dev
-entry as done for the \fB-s\fP, send SG_IO commands to
+entry as done for the \fB\-s\fP, send SG_IO commands to
\fBdevice\fP, such as \fB/dev/sdc\fP.
+This argument should also be used when invoked via udev to avoid problems
+with creation of temporary files on not-yet writable directories.
.TP
-.BI \-e
-Send all output to standard error even if
-.B scsi_id
-is running in hotplug mode.
-.TP
-.BI \-f "\| config-file"
+.BI \-f "\| config\-file"
Read configuration and black/white list entries from
-.B config-file
+.B config\-file
rather than the default
.B /etc/scsi_id.config
file.
Prefix the identification string with the driver model (sysfs) bus id of
the SCSI device.
.TP
-.BI \-p "\| 0x80 | 0x83"
-Use SCSI INQUIRY VPD page code 0x80 or 0x83. The default behaviour is to
-query the available VPD pages, and use page 0x83 if found, else page 0x80
-if found, else nothing.
+.BI \-p "\| 0x80 | 0x83 | pre-spc3-83"
+Use SCSI INQUIRY VPD page code 0x80, 0x83, or pre-spc3-83.
+.sp
+The default
+behaviour is to query the availabe VPD pages, and use page 0x83 if found,
+else page 0x80 if found, else nothing.
+.sp
+Page pre-spc3-83 should only be utilized for those scsi devices which
+are not compliant with the SPC-2 or SPC-3 format for page 83. While this
+option is used for older model 4, 5, and 6 EMC Symmetrix devices, its
+use with SPC-2 or SPC-3 compliant devices will fallback to the page 83
+format supported by these devices.
.TP
-.BI \-s "\|sysfs-device"
+.BI \-s "\| sysfs\-device"
Generate an id for the
-.B sysfs-device.
+.B sysfs\-device.
The sysfs mount point must not be included. For example, use /block/sd,
not /sys/block/sd.
.TP
+.BI \-u
+Reformat the output : replace all whitespaces by underscores.
+.TP
+.BI \-x
+Export all data in KEY=<value> format used to import in other programs.
+.TP
.BI \-v
Generate verbose debugging output.
.TP
.BI \-V
Display version number and exit.
.RE
+
+.SH USAGE WITH UDEV
+
+If \fBscsi_id\fP is invoked with one argument without a leading \-, it
+assumes it is called for a hotplug event, and looks for the sysfs device
+in the DEVPATH environment variable. This mode is deprecated, but
+available for backwards compatibility.
+
+If the DEVPATH environment variable is set, scsi_id assumes it has been
+invoked via udev (or some other hotplug program), and all errors or
+warnings are sent using syslog.
+
+To determine the specific value needed in a RESULT key, use the \-s option,
+for example:
+
+.sp
+.nf
+/sbin/scsi_id -s /block/sda
+.fi
+.P
+
+\fBscsi_id\fP is one of the tools used in the "Linux Persistent Device Names"
+scheme that creates persistent device links in /dev/disk. It is called with
+the -x option which will print all values in a defined format to let udev
+import it into its own environment for later event processing.
+.sp
+An example custom \fBudev\fP rule using \fBscsi_id\fP, that will name a block
+device and any partitions for the device matching the \fBscsi_id\fP output
+of 312345:
+
+.sp
+.nf
+BUS=="scsi", PROGRAM=="/sbin/scsi_id -d %N -s %p", RESULT=="312345", NAME="disk%n"
+.fi
+.P
+
.SH "FILES"
.nf
.ft B
.LP
.SH "SEE ALSO"
.BR udev (8)
-, especially the CALLOUT method.
.SH AUTHORS
Developed by Patrick Mansfield <patmans@us.ibm.com> based on SCSI ID
source included in earlier linux 2.5 kernels, sg_utils source, and SCSI