User's Manual

Glossary
alternate group A PRM group other than the user’s initial group that a user can access using prmrun or prmmove.
For users, these groups are listed in their user records (or their netgroups’ user records) in the
PRM configuration file following the initial group. Root users can access all PRM groups, so
alternate groups need not be specified in their user record.
alternate name Other names assigned to processes spawned by an application. This is most common for complex
programs such as database and mail programs that launch many processes and rename them.
application
manager
A daemon that polls the PRM configuration file and the running processes to ensure all processes
are in the proper PRM groups.
application record Record in a PRM configuration file that specifies the PRM group an application is to run in. This
record can optionally specify any alternate names an application may take upon execution.
available memory The amount of real memory not reserved for the kernel or root processes. Available memory is
used by the system for executing user processes.
child group In a hierarchy, a PRM group that has a parent group.
compartment You create a compartment configuration using the HP-UX feature Security Containment, which is
available starting with HP-UX 11i v2 (B.11.23). You can also use a PRM utility such as srpgen
or prm2scomp. PRM then allows you to map your compartments to PRM groups so you can
control resource allocation.
configuration file File (/etc/prmconf by default) that PRM uses to determine group names, resource shares,
applications’ assigned groups, and other items. Additional configuration files are typically stored
in the directory /etc/opt/prm/conf, with the owner set to hpsmh. You can edit these files with a
text editor, the PRM interface in HP System Management Homepage, or the PRM interface in HP
Systems Insight Manager.
core The actual data-processing engine within a processor. A single processor might have multiple
cores. A core might support multiple execution threads.
CPU cap An upper limit on a group’s [LINEBREAK]CPU resource use. PRM caps CPU consumption for FSS
PRM groups using either CPUCAPON mode (enabled through prmconfig) or per-group capping
(available for HP-UX 11i v3 and later), which uses the MAX field in the group record.
CPU manager PRM uses the Fair Share Scheduler (FSS) to manage CPU resources for FSS PRM groups. For PSET
PRM groups, processes have equal access to CPU cycles through the HP-UX standard time-share
scheduler.
effective user ID A form of user ID that can allow users access to files they do not own.
file ID ID used by the application manager to place processes in the appropriate PRM groups. The file
ID is based on the file system device and inode number.
group/CPU record Record in a PRM configuration file that specifies a PRM group’s name and its CPU allocation.
PRM requires two groups: PRM_SYS (PRMID 0) for system processes and OTHERS (PRMID 1) for
users without user records. PRM automatically creates the PRM_SYS group.
hierarchy An FSS PRM group hierarchy is a nesting of groups. You specify resource shares at each level
of the hierarchy. If a group has child groups, the parent group’s resource shares are distributed
to the children based on the shares they are assigned. If a group has no child groups, it uses the
shares itself.
HP-UX real-time
process
A process that uses the HP-UX real-time scheduler (rtprio). This type of process keeps its assigned
priorities because timely scheduling is crucial to the operation of a real-time process. Hence, a
real-time process is permitted to exceed its group’s CPU share and max.
initial group The first PRM group listed in a user record in a configuration file. Typically, the applications a
user launches run in the user’s initial group—assuming those applications do not have their own
application records. This is the group prmconfig, prmmove -i, login, at, and cron use
to determine where to place user processes. If a user does not have a user record or is not in a
netgroup that has a user record, the user default group OTHERS becomes the user’s initial group.
leaf group Any PRM group that has no children (child groups). In a configuration that does not use group
hierarchies, all the groups are leaf groups.
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