System Tunable Mapping: Tru64 UNIX to HP-UX 11i v2
for Tru64 UNIX and 2048 for HP-UX. The maximum value allowed on this parameter is different for
Tru64 UNIX and HP-UX. The maximum value for Tru64 UNIX is INT_MAX; the maximum value for
HP-UX is semmns. The default value for semmns is 4096; and the maximum value is 335534080 for
HP-UX.
sem_msl (Tru64 UNIX) versus semmsl (HP-UX)
This parameter specifies the maximum number of individual System V IPC semaphores per semaphore
identifier (ID). If an application attempts to exceed this limit, it will receive an [EINVAL] error from
semget().
The default value of this parameter is different for Tru64 UNIX and HP-UX. The default setting is 25 for
Tru64 UNIX, and 2048 for HP-UX. The maximum value allowed on this parameter is different for
Tru64 UNIX and HP-UX. It is INT_MAX for Tru64 UNIX; while it is 10240 for HP-UX.
sem_ume (Tru64 UNIX) versus semume (HP-UX)
This parameter specifies the maximum number of System V IPC semaphores upon which a single
process can have outstanding (nonzero) "undo" operations.
The default value of this parameter is different for Tru64 UNIX and HP-UX. The default setting is 10 for
Tru64 UNIX and 100 for HP-UX. The maximum value allowed on this parameter is different for Tru64
UNIX and HP-UX. The maximum value for Tru64 UNIX is INT_MAX; the maximum value for HP-UX is
semmns. The default value of semmns is 4096; and the maximum value is 335534080.
sem_vmx (Tru64 UNIX) versus semvmx (HP-UX)
This parameter specifies the maximum value any given System V IPC semaphore can have.
The default value and maximum values for this parameter are the same for Tru64 UNIX and HP-UX.
Note: On HP-UX, the semmns tunable specifies the number of System V IPC systemwide
semaphores; the semmnu tunable specifies the maximum number of System V IPC undo structures for
processes. These two tunables do not exist on Tru64 UNIX.
System V Shared Memory Attributes
The following table shows the system tuning options for System V shared memory attributes:
Tru64 UNIX HP-UX Dynamic on HP-UX Description
shm_seg
shmseg
Yes Maximum number of System V shared
memory segments per process.
shm_mni
shmmni
Yes Number of System V shared memory
segment identifiers in the system.
shm_max
shmmax
Yes Maximum size, in bytes, for a System V
shared memory segment.
shm_seg (Tru64 UNIX) versus shmseg (HP-UX)
This parameter specifies the maximum number of System V shared memory segments per process.
The default value of this parameter is different for Tru64 UNIX and HP-UX. The default setting is 32 for
Tru64 UNIX and 300 for HP-UX. The maximum value allowed on this parameter is different for Tru64
UNIX and HP-UX. The maximum value for Tru64 UNIX is 2^31-1; the maximum value for HP-UX is
any value less than or equal to
shmmni.
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