SCSI_ID(8) Linux Administrators Manual SCSI_ID(8)
scsi_id - retrieve and generate a unique SCSI identifier
scsi_id queries a SCSI device via the SCSI INQUIRY vital product data
(VPD) page 0x80 or 0x83 and uses the resulting data to generate a value
that is unique across all SCSI devices that properly support page 0x80
or page 0x83.
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.
scsi_id is primarily for use by other utilities such as udev that
require a unique SCSI identifier.
By default all devices are assume black listed, the -g option must be
specified on the command line or in the config file for any useful
SCSI commands are sent directly to the device via the SG_IO ioctl
In order to generate unique values for either page 0x80 or page 0x83,
the serial numbers or world wide names are prefixed as follows.
Identifiers based on page 0x80 are prefixed by the character S, the
SCSI vendor, the SCSI product (model) and then the the serial number
returned by page 0x80. For example:
# scsi_id -p 0x80 -s /block/sdg
SIBM 3542 1T05078453
Identifiers based on page 0x83 are prefixed by the identifier type fol
lowed by the page 0x83 identifier. For example, a device with a NAA
(Name Address Authority) type of 3 (also in this case the page 0x83
identifier starts with the NAA value of 6):
# /sbin/scsi_id -p 0x83 -s /block/sdg
Deprecated method: when called with only a single argument with
out a leading -, runs in a hotplug mode, and expects the envi
ronment variable DEVPATH to specify the corresponding sysfs
device. See section below on usage with udev.
-a Always print information (model, vendor strings) about the
device even if it does not support VPD pages.
-b The default behaviour - treat the device as black listed, and do
nothing unless a white listed device is found in the scsi_id
Instead of determining and creating a device node based on a
sysfs dev entry as done for the -s, send SG_IO commands to
device, such as /dev/sdc. This argument should also be used
when invoked via udev to avoid problems with creation of tempo
rary files on not-yet writable directories.
Read configuration and black/white list entries from config-file
rather than the default /etc/scsi_id.config file.
-g Treat the device as white listed. The -g option must be speci
fied on the command line or in the scsi_id configuration file
for scsi_id to generate any output.
-i Prefix the identification string with the driver model (sysfs)
bus id of the SCSI device.
-p 0x80 | 0x83 | pre-spc3-83
Use SCSI INQUIRY VPD page code 0x80, 0x83, or pre-spc3-83.
The default behaviour is to query the available VPD pages, and
use page 0x83 if found, else page 0x80 if found, else nothing.
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.
Generate an id for the sysfs-device. The sysfs mount point must
not be included. For example, use /block/sd, not /sys/block/sd.
-u Reformat the output : replace all whitespaces by underscores.
-x Export all data in KEY= format used to import in other
-v Generate verbose debugging output.
-V Display version number and exit.
USAGE WITH UDEV
If scsi_id 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:
/sbin/scsi_id -s /block/sda
scsi_id 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.
An example custom udev rule using scsi_id, that will name a block
device and any partitions for the device matching the scsi_id output of
BUS=="scsi", PROGRAM=="/sbin/scsi_id -d %N -s %p", RESULT=="312345", NAME="disk%n"
/etc/scsi_id.config configuration and black/white list entries
Developed by Patrick Mansfield based on SCSI ID
source included in earlier linux 2.5 kernels, sg_utils source, and SCSI
December 2003 SCSI_ID(8)