swapmem_on(5) OBSOLETE swapmem_on(5)NAMEswapmem_on - OBSOLETE kernel tunable parameter
DESCRIPTION
The tunable is obsolete. Processes will always be allowed to use
pseudo-swap space if it is available.
In previous versions of HP-UX, system configuration required sufficient
physical swap space for the maximum possible number of processes on the
system. This is because HP-UX reserves swap space for a process when
it is created, to ensure that a running process never needs to be
killed due to insufficient swap.
This was difficult, however, for systems needing gigabytes of swap
space with gigabytes of physical memory, and those with workloads where
the entire load would always be in core. This tunable was created to
allow system swap space to be less than core memory. To accomplish
this, a portion of physical memory is set aside as "pseudo-swap" space.
While actual swap space is still available, processes still reserve all
the swap they will need at fork or execute time from the physical
device or file system swap. Once this swap is completely used, new
processes do not reserve swap, and each page which would have been
swapped to the physical device or file system is instead locked in mem‐
ory and counted as part of the pseudo-swap space.
WARNINGS
Installation of optional kernel software, from HP or other vendors, may
cause changes to tunable parameter values. After installation, some
tunable parameters may no longer be at the default or recommended val‐
ues. For information about the effects of installation on tunable val‐
ues, consult the documentation for the kernel software being installed.
For information about optional kernel software that was factory
installed on your system, see at
AUTHOR
was developed by HP.
Tunable Kernel Parameters swapmem_on(5)
