HP-UX Reference (11i v1 00/12) - 1M System Administration Commands N-Z (vol 4)
__________________________________________________________________________________________________________________________________________________________________________________________________
__________________________________________________________________________________________________________________________________________________________________________________________________
STANDARD Printed by: Nora Chuang [nchuang] STANDARD
/build/1111/BRICK/man1m/naaagt.1m
________________________________________________________________
___ ___
s
swapinfo(1M) swapinfo(1M)
NAME
swapinfo - system paging space information
SYNOPSIS
/usr/sbin/swapinfo [-mtadfnrMqw]
DESCRIPTION
swapinfo prints information about device and file system paging space. (Note: the term ‘swap’ refers to
an obsolete implementation of virtual memory; HP-UX actually implements virtual memory by way of pag-
ing rather than swapping. This command and others retain names derived from ‘swap’ for historical rea-
sons.)
By default, swapinfo prints to standard output a two line header as shown here, followed by one line per
paging area:
Kb Kb Kb PCT START/ Kb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
The fields are:
TYPE One of:
dev Paging space residing on a mass storage device, either taking up the entire device
or, if the device contains a file system, taking up the space between the end of the
file system and the end of the device. This space is exclusively reserved for paging,
and even if it is not being used for paging, it cannot be used for any other purpose.
Device paging areas typically provide the fastest paging.
fs Dynamic paging space availablefrom a file system. When this space is needed, the
system creates files in the file system and uses them as paging space. File system
paging is typically slower than device paging, but allows the space to be used for
other things (user files) when not needed for paging.
localfs File system paging space (see fs above) on a file system residing on a local disk.
network File system paging space (see fs above) on a file system residing on another
machine. This file system would have been mounted on the local machine via NFS.
reserve Paging space on reserve. This is the amount of paging space that could be needed
by processes that are currently running, but that has not yet been allocated from
one of the above paging areas. See "Paging Allocation" below.
memory Memory paging area (also known as pseudo-swap). This is the amount of system
memory that can be used to hold pages in the event that all of the above paging
areas are used up. See "Paging Allocation" below. This line appears only if
memory paging is enabled.
Kb AVAIL The total available space from the paging area, in blocks of 1024 bytes (rounded to nearest
whole block if necessary), including any paging space already in use.
For file system paging areas the value is not necessarily constant. It is the current space allo-
cated for paging (even if not currently used), plus the free blocks available on the file system to
ordinary users, minus RESERVE (but never less than zero). AVAIL is never more than LIMIT
if LIMIT is non-zero. Since paging space is allocated in large chunks, AVAIL is rounded down
to the nearest full allocation chunk.
For the memory paging area this value is also not necessarily constant, because it reflects allo-
cation of memory by the kernel as well as by processes that might need to be paged.
Kb USED The current number of 1-Kbyte blocks used for paging in the paging area. For the memory
paging area, this count also includes memory used for other purposes and thus unavailable for
paging.
Kb FREE The amount of space that can be used for future paging. Usually this is the difference between
Kb AVAIL and Kb USED. There could be a difference if some portion of a device paging area
is unusable, perhaps because the size of the paging area is not a multiple of the allocation
chunk size, or because the tunable parameter maxswapchunks
is not set high enough.
PCT USED The percentage of capacity in use, based on Kb USED divided by Kb AVAIL; 100% if Kb AVAIL
is zero.
Section 1M−−840 − 1 − HP-UX Release 11i: December 2000
___
___