HP Management Base Installation and User's Guide (May 2006)

Refer to hpbmc (8) for an explanation of all directives. This section discusses some of the background
processing done by hpmgmtbase and hpbmc.
All IPMI commands are a command/response message protocol with a requestor and a responder . In most
cases on HP hardware using HP software, programs running under Linux are the requestor, and the system's
BMC is the responder.
The BMC hardware is exposed through a System Interface as described in the IPMI specification. This channel
requires a device driver and device file to exchange commands and responses. The hpmgmtbase installation
will load the Open IPMI driver modules and set up the character device files /dev/ipmi/0 and
/dev/ipmi0. These files are well-known to the Linux Open IPMI community (such as ipmitool).
By default, hpbmc uses these files to access the local BMC. SELprint is implemented similar the following
conversation:
BMChpbmc
Respond "there is an SDR, a SEL, ..."Send "Get BMC Capabilities"
Respond "there are xxxx entries"Send "Get SEL Capabilities"
Respond with entry nnnnWhile more SEL entries
Send "Get SEL entry nnnn"
Decode and print entry nnnn
Another task done at hpmgmtbase installation is caching of the Sensor Data Record Repository (SDRR). IPMI
is intended to be self-describing and the SDRR holds the material list for the system (along with sensors).
Software can construct a coherent view of the entire system starting from this material list.
The SDRR is thus crucial to the completion of most hpbmc directives. Not only is the SDRR a large list, the
IPMI interface is a relatively slow channel. It can take over twenty seconds to read the SDRR on some Integrity
servers. Fortunately the SDRR is a static collection on Integrity Servers and can easily be cached to a disk
file. This is done at hpmgmtbase installation and by default hpbmc will read this cache.
The -d path option changes the path to the BMC. The HPBMC_DEVICE environment variable can be set
for the same purpose. Specifying an alternate Open IPMI device file is of interest only to IPMI utility developers
and is usually not seen in practice.
hpmgmtbase utilities also support the Remote Management Control Protocol (RMCP), or IPMI over LAN. This
works against any BMC (or IPMI controller) which speaks RMCP. An RMCP exchange always needs a host
target (DNS name or IP address), and optionally a password and user name. The path argument then takes
the form
[[user:]password]@hostname
Either use the -d option or set HPBMC_DEVICE. Here are some things to remember:
• Early entry-level Integrity Servers may not have an MP card.
• Early entry-level MP card firmware does not support RMCP. The MP firmware must be upgraded to at
least E.03.15 for RMCP support. The MP card is then known as the Integrity iLO Card as it is similar
in functionality to the HP ProLiant iLO cards.
• On entry-level Integrity iLO, RMCP access is turned OFF by default. It is enabled through the command
line interface of the MP card using the SA command.
• The IPMI password on all HP Integrity Servers is unset (or null) by default.
• On midrange and highend systems the RMCP password can be set through the MP card command line
interface. Entry-level systems only support RMCP password changes over RMCP; see the RMCPpasswd
directive of hpbmc.
The final complexity in addressing an IPMI responder or target device is the IPMI Bus, or IPMB. IPMB is an
address-based I2C bus that passes IPMI commands back and forth between intelligent controllers.
Some HP Integrity Servers do have IPMB, but its use is hidden by hpbmc and not directly exposed. However,
on the HP ATCA platform this functionality is of immense interest. Consult ATCA documentation for details.
The IPMI Send Message command is used to bridge data from external sources (System Interface or RMCP)
to and from an IPMB behind the BMC. The -b argument to hpbmc takes a hexadecimal IPMB address to
12 Using hpmgmtbase