.fi
.P
-
.SH OPTIONS
.TP
+.BI subsystem
+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 \-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.
entry as done for the \fB-s\fP, send SG_IO commands to
\fBdevice\fP, such as \fB/dev/sdc\fP.
.TP
-.BI \-e
-Send all output to standard error even if
-.B scsi_id
-is running in hotplug mode.
-.TP
.BI \-f "\| config-file"
Read configuration and black/white list entries from
.B config-file
query the available VPD pages, and use page 0x83 if found, else page 0x80
if found, else nothing.
.TP
-.BI \-s "\|sysfs-device"
+.BI \-s "\| sysfs-device"
Generate an id for the
.B sysfs-device.
The sysfs mount point must not be included. For example, use /block/sd,
.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 used when run via the \fBudev\fP PROGRAM key. Passing any
+arguments or options as part of the PROGRAM rule breaks this assumption,
+and the results will likely not be as expected.
+
+When in this mode, all errors and warnings are sent via 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
+
+An example \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", RESULT="312345", NAME="disk%n"
+.fi
+.P
+
.SH "FILES"
.nf
.ft B
.fi
.LP
.SH "SEE ALSO"
-.BR udev (8)
-, especially the CALLOUT method.
+.BR udev (8), hotplug (8)
.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