Provided by: smp-utils_0.99-1_amd64 
NAME
smp_* - invoke a SAS Serial Management Protocol (SMP) function
SYNOPSIS
smp_* [--expected=EX] [--help] [--hex] [--interface=PARAMS] [--raw] [--sa=SAS_ADDR]
[--verbose] [--version] SMP_DEVICE[,N]
DESCRIPTION
Serial Attached SCSI (SAS) is a transport (also known as a interconnect) used by storage
systems. A SAS system is made up of Host Bus Adapters (HBAs typically containing SCSI
initiators), disks (referred to in SCSI as both targets and logical units) and optionally
some switching hardware called "expanders". Expanders are not SCSI devices so a new
protocol was required to control and monitor them. The protocol's full name is the SAS
Serial Management Protocol which is abbreviated to SMP.
smp_utils is a package of utilities. Each utility sends an SMP function request to a
SMP_DEVICE (an SMP target). Some utilities may invoke the same function more than once. If
an error occurs then an error message is sent to stderr. If no error occurs, the response
is decoded (the default), output in ASCII hex (when --hex is given) or output in binary to
stdout (when the --raw option is given).
If SMP_DEVICE[,N] is not given then the value in the environment variable SMP_UTILS_DEVICE
is used.
This package was originally written for Linux and has been ported to FreeBSD and Solaris.
LINUX INTERFACE
Currently there are multiple interfaces that allow SMP functions to be passed through to
an SMP target.
One method is to have a SMP_DEVICE which is actually the SMP initiator (e.g.
'/dev/mptctl,0'). In this case the SMP target's SAS address must be supplied with the
--sa=SAS_ADDR option.
Another method is to have a SMP_DEVICE which represents the SMP target. In this case no
SAS_ADDRESS needs to be given (since it is implicit).
Each utility in smp_utils attempts to work out which interface it has been given by
examining the SMP_DEVICE file. There are three interfaces supported currently:
aac This specifies the aacraid SAS pass-through associated with Adaptec/PMC RAID
products. The SMP_DEVICE[,N] argument takes the form /dev/aac[N[,E_ID]] where "N"
is the raid controller number (typically 0) and "E_ID" is the expander identifier
(typically 0); both default to 0 so /dev/aac is equivalent to /dev/aac0 and
/dev/aac0,0 . The "N" is the unique_id found in /sys/class/scsi_host<HN>/unique_id
. The "HN" is the host number which is the first number to appear on each line in
the lsscsi utility which by default uses one line to list each accessible SCSI
device (typically SCSI or ATA disks). The "E_ID" is the expander identifier which
can be found with the Adaptec/PMC arcconf utility using the form "arcconf
expanderlist <ControllerNum>". The <ControllerNum>s start at 1 . If an aac RAID
controller is present then the /dev/acc device node will be created by the first
smp utility to use this interface.
mpt This specifies the MPT fusion SAS pass-through. The mptsas driver uses the
'/dev/mptctl' device node (character device major 10, minor 220) while the mpt2sas
driver uses '/dev/mpt2ctl' device node (major 10, minor 221). For the mpt3sas
driver the corresponding device node is '/dev/mpt3ctl'. The 'modprobe mptctl' or
'modprobe mpt2ctl' command may be needed. If there are multiple mpt fusion
controllers (HBAs) in the computer, then the user will need to specify which one to
use with the syntax: '/dev/mptctl,<n>' where <n> is the "ioc_num". This number can
be found with dmesg after the mptsas driver is registered and appears as a suffix
to the driver name (e.g. mpt2sas0). It can also be found in
'/sys/class/scsi_host/host<n>/unique_id'. When this interface is used the
--sa=SAS_ADDR option must be given to specify the SAS address of the SMP target.
sgv4 (sg)
This interface is more generic and supported by several SAS HBA drivers including
mptsas (and mpt2sas). It was introduced in the Linux 2.6.24 kernel. The SMP
functions are passed to the kernel via the bsg driver using a format known as "SCSI
Generic Version 4" which gives this interface its name: "sgv4" or just "sg". The
SAS transport layer within the SCSI sub-system unpacks the SMP requests and
forwards them to SAS low level drivers that support this interface. The SMP_DEVICE
is either a member of the '/sys/class/bsg' directory (e.g.
/sys/class/bsg/expander-6:0 ) or a device node made for the bsg driver (e.g.
/dev/bsg/expander-6:0 ). Such device nodes are dynamic (i.e. they don't have fixed
major and minor numbers) and should correspond to the major and minor numbers found
in the 'sys/class/bsg/<smp_target_device>/dev' file.
FREEBSD INTERFACE
The CAM subsystem has been enhanced in FreeBSD 9 to pass-through SMP requests and return
the corresponding responses. However CAM does not directly access expander devices because
they are not SCSI devices. It makes the assumption that each SAS expander has an
integrated SES (enclosure) device and that is addressed. This assumption seems to be true
for SAS-2 expanders but not some SAS-1 expanders. Thus invocations look like this:
# smp_discover /dev/ses0
where /dev/ses0 is a SES device associated with a SAS expander.
SOLARIS INTERFACE
The USMP pass-through mechanism is used. Invocations look like this:
# smp_rep_manufacturer /dev/smp/expd0
ENVIRONMENT VARIABLES
If the device name is not given then the SMP_UTILS_DEVICE environment variable is checked
and if present its contents are used as the device name.
If the SAS address (of the SMP target) is not given and it is required (i.e. it is not
implicit in the device name) then the SMP_UTILS_SAS_ADDR environment variable is checked
and if present its contents are used as the SAS address. SAS addresses are usually given
in hex indicated by a leading '0x' or trailing 'h'.
A device slot number (dsn) is important for establishing the relationship between an
expander phy and a SES array element. Newer expanders (e.g. SAS-3) support dsn_s in the
DISCOVER (and DISCOVER LIST) functions. These can be shown, if available, with the --dsn
option to smp_discover and smp_discover_list utilities.. To ease typing that option often,
the SMP_UTILS_DSN environment variable, if present, has the same effect.
If both an environment variable and the corresponding command line option is given and
contradict, then the command line options take precedence.
COMMON OPTIONS
Mandatory arguments to long options are mandatory for short options as well. If an option
takes a numeric argument then that argument is assumed to be decimal unless otherwise
indicated (e.g. with a leading "0x" or a trailing "h").
-E, --expected=EX
revision 4a of the SAS-2 draft introduced an 'expected expander change count' field
in some SMP requests. The idea is to detect other SMP initiators trying to change
the state of an expander. The value EX is from 0 to 65535 inclusive with 0 being
the default value. When EX is greater than zero then if the value doesn't match the
expander change count of the SMP target (i.e. the expander) when the request
arrives then the target ignores the request and sets a function result of "invalid
expander change count" in the response.
-h, --help
output the usage message for the utility then exit.
-H, --hex
output the response in hexadecimal. This does not include the trailing CRC field.
-I, --interface=PARAMS
interface specific parameters. This option is usually not needed since the
interface type is guessed by a utility based on the characteristics of the given
SMP_DEVICE argument or what is in the corresponding environment variables. PARAMS
is of the form: INTF[,force]. If the guess doesn't work then the interface can be
specified by giving a INTF of either 'mpt' or 'sgv4'. Sanity checks are still
performed and a utility may refuse if it doesn't agree with the given INTF. If the
user is really sure then adding a ',force' will force the utility to use the given
interface.
-r, --raw
send the response to stdout in binary. This does not include the trailing CRC
field. All error messages are sent to stderr.
-s, --sa=SAS_ADDR
specifies the SAS address of the SMP target device. Typically this is an expander.
This option may not be needed if the SMP_DEVICE has the target's SAS address
associated with it. The SAS_ADDR is in decimal but most SAS addresses are shown in
hexadecimal. To give a number in hexadecimal either prefix it with '0x' or put a
trailing 'h' on it. If this option is not given then the value in the environment
variable SMP_UTILS_SAS_ADDR is used.
-v, --verbose
increase the verbosity of the output. Can be used multiple times.
-V, --version
print the version string and then exit.
EXIT STATUS
To aid scripts that call these utilities, the exit status is set to indicate success (0)
or failure (1 or more):
0 success
1 - 63 reserved for SMP function result codes. See the SAS-2 (or later) draft, in the
section on the application layer, drilling down further: management application
layer then SMP functions. Here are some common function result codes: 1 [unknown
SMP function], 2 [SMP function failed], 16 [phy does not exist], 17 [index does not
exist], 18 [phy does not support SATA], 19 [unknown phy operation], 22 [phy vacant]
and 35 [zone lock violation].
91 syntax error. Either illegal options, options with bad arguments or a combination
of options that is not permitted.
92 the utility is unable to open, close or use the given SMP_DEVICE. The given file
name could be incorrect or there may be file permission problems. Adding the
--verbose option may give more information.
93 the utility has a resource problem. Typically this means an attempt to allocate
memory (ram) has failed.
97 the response to an SMP function failed sanity checks.
99 any error that can't be categorized into values 1 to 97 may yield this value. This
includes transport and operating system errors.
126 the utility was found but could not be executed. That might occur if the executable
does not have execute permissions.
127 This is the exit status for utility not found. That might occur when a script calls
a utility in this package but the PATH environment variable has not been properly
set up, so the script cannot find the executable.
128 + <signum>
If a signal kills a utility then the exit status is 128 plus the signal number. For
example if a segmentation fault occurs then a utility is typically killed by
SIGSEGV which according to 'man 7 signal' has an associated signal number of 11; so
the exit status will be 139 .
255 the utility tried to yield an exit status of 255 or larger. That should not happen;
given here for completeness.
NOTES
Finding the SAS address of an expander can be a challenge in some environments. An
enclosure containing one or more expanders may have the expander SAS address(es) printed
on the back of the device, a bit like Ethernet MAC addresses.
In the Linux 2.6 kernel series the expander SAS address may well be in the sysfs tree but
it is not always easy to find. Doing this search may help:
# find /sys -name "*expander*"
That should show the suffix on any expanders that have been detected. Then a command like
'cat /sys/class/sas_device/expander-6:0/sas_address' should show its SAS address.
Another approach is to work backwards from SCSI devices (i.e. logical units). The protocol
specific port log page (log page 18h) contains fields for the "attached SAS address". The
sg_logs utility from the sg3_utils package could be used like this:
# sg_logs --page=18h /dev/sdb
Any given "attached SAS address" is either a HBA, an expander or 0 indicating that port is
not connected. An expander is indicated by "attached device type: expander device". A SAS
disk's target port identifiers (also known as SAS addresses), device name and logical unit
name (all NAA 5 format) can be found with the sg_vpd utility (e.g. 'sg_vpd -i
<disk_dev>'). The sdparm utility can provide the same information (e.g. 'sdparm -i
<disk_dev>').
A SAS expander is often associated with a SCSI Enclosure Services (SES) device sometimes
on the same silicon attached via a virtual phy to the expander. That SES device may be
able to access and control an attached enclosure or backplane via SGPIO or I2C on sideband
signals (e.g. in a SFF-8087 cable). To interact with a SES device, see the sg_ses utility.
Often expander phys are grouped in fours on the same connector (e.g. SFF-8088). Care
needs to be taken when multiple expanders are interconnected. An enclosure universal port
is one in which the "table to table supported" attribute is set (in the REPORT GENERAL
response) and the associated phys have the table routing attribute (in the DISCOVER
response). Enclosure universal ports were introduced in SAS-2 and have few restrictions
when used to interconnect expanders or connect SAS or SATA devices. An enclosure out port
is one in which the "table to table supported" attribute is clear and the associated phys
have the table routing attribute. An enclosure in port is one in which the associated phys
have the subtractive routing attribute. When universal ports are not available, an
expander interconnect should be between an in port and an out port.
EXAMPLES
See "Examples" section in http://sg.danny.cz/sg/smp_utils.html .
CONFORMING TO
SAS has multiple generations. The early standards are: the original SAS (ANSI INCITS
376-2003), SAS 1.1 (INCITS 417-2006) and SAS-2 (ANSI INCITS 457-2010) . SAS-2.1 work was
split into an electrical and physical layers document (standardized as SAS-2.1 ANSI INCITS
478-2011) with the upper level layers placed in a document called the SAS Protocol Layer
and it was standardized as SPL ANSI INCITS 476-2011. Next came SPL-2 which was
standardized as SPL-2 ANSI INCITS 505-2013. Then came SPL-3 which was standardized as
SPL-3 ANSI INCITS 492-2015. SPL-4 is near standardization and its most recent draft is
spl4r13.pdf while SPL-5 work has started and its most recent draft is spl5r03.pdf. To
lessen confusion, the multiple generations of SAS will be referred to in these man pages
as SAS 1, 1.1, 2, 2.1 (SPL), 3 (SPL-2 and SPL-3), 4 (SPL-4) and 5 (SPL-5). Roughly
speaking for the electrical and physical layers standards SAS-1 runs at 3 Gbps, SAS-2 at 6
Gbps, SAS-3 at 12 Gbps and SAS-4 at 22.5 Gbps. Drafts, including those just prior to
standardization can be found at the http://www.t10.org site (e.g. spl-r07.pdf and
spl2r04c.pdf). INCITS policy now requires a registration to view these drafts, a break
from t10.org tradition.
The two utilities for reading and writing to GPIO registers, smp_read_gpio and
smp_write_gpio, are defined in the Small Form Factor document SFF-8485 found at
http://www.sffcommittee.com . "Enhanced" versions of the corresponding SMP functions have
been mentioned in some drafts but no definitions have been published and the references
have been removed in more recent drafts.
In this section of each utility's man page is the first standard in which the associated
SMP function appeared and whether there have been significant additions in later
standards.
The COVERAGE file in the smp_utils source tarball shows a table of all SMP function names
defined in the drafts, the versions of those standards in which those SMP functions first
appeared and the corresponding smp_utils utility names. A lot of extra SMP functions have
been added in SAS-2 associated with zoning.
AUTHORS
Written by Douglas Gilbert.
REPORTING BUGS
Report bugs to <dgilbert at interlog dot com>.
COPYRIGHT
Copyright © 2006-2020 Douglas Gilbert
This software is distributed under a FreeBSD license. There is NO warranty; not even for
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
SEE ALSO
sg_logs, sg_vpd, sg_ses(sg3_utils); sdparm(sdparm); lsscsi(lsscsi)