VM_STAT(1) BSD General Commands Manual VM_STAT(1)NAME
vm_stat -- show Mach virtual memory statistics
SYNOPSIS
vm_stat [[-c count] interval]
DESCRIPTION
vm_stat displays Mach virtual memory statistics. If the optional interval is specified, then vm_stat will display the statistics every
interval seconds. In this case, each line of output displays the change in each statistic (an interval count of 1 displays the values per
second). However, the first line of output following each banner displays the system-wide totals for each statistic. If a count is pro-
vided, the command will terminate after count intervals. The following values are displayed:
Pages free
the total number of free pages in the system.
Pages active
the total number of pages currently in use and pageable.
Pages inactive
the total number of pages on the inactive list.
Pages speculative
the total number of pages on the speculative list.
Pages throttled
the total number of pages on the throttled list (not wired but not pageable).
Pages wired down
the total number of pages wired down. That is, pages that cannot be paged out.
Pages purgeable
the total number of purgeable pages.
Translation faults
the number of times the "vm_fault" routine has been called.
Pages copy-on-write
the number of faults that caused a page to be copied (generally caused by copy-on-write faults).
Pages zero filled
the total number of pages that have been zero-filled on demand.
Pages reactivated
the total number of pages that have been moved from the inactive list to the active list (reactivated).
Pages purged
the total number of pages that have been purged.
File-backed pages
the total number of pages that are file-backed (non-swap)
Anonymous pages
the total number of pages that are anonymous
Uncompressed pages
the total number of pages (uncompressed) held within the compressor
Pages used by VM compressor:
the number of pages used to store compressed VM pages.
Pages decompressed
the total number of pages that have been decompressed by the VM compressor.
Pages compressed
the total number of pages that have been compressed by the VM compressor.
Pageins
the total number of requests for pages from a pager (such as the inode pager).
Pageouts
the total number of pages that have been paged out.
Swapins
the total number of compressed pages that have been swapped out to disk.
Swapouts
the total number of compressed pages that have been swapped back in from disk.
If interval is not specified, then vm_stat displays all accumulated statistics along with the page size.
Mac OS X August 13, 1997 Mac OS X
Check Out this Related Man Page
vmstat(1) General Commands Manual vmstat(1)NAME
vmstat - report virtual memory statistics
SYNOPSIS
[interval [count]]
| |
DESCRIPTION
The command reports certain statistics kept about process, virtual memory, trap, and CPU activity. It also can clear the accumulators in
the kernel structure.
Options
recognizes the following options:
Report disk transfer information as a separate section,
in the form of transfers per second.
Provide an output format
that is more easily viewed on an 80-column display device. This format separates the default output into two groups: vir-
tual memory information and CPU data. Each group is displayed as a separate line of output. On multiprocessor systems,
this display format also provides CPU utilization on a per CPU basis for the active processors.
Report the number of processes swapped in and out
and instead of page reclaims and address translation faults and
interval Display successive lines which are summaries over the last interval seconds. The first line reported is for the time
since a reboot and each subsequent line is for the last interval only. If interval is zero, the output is displayed once
only. If the option is specified, the column headers are repeated. If is omitted, the column headers are not repeated.
The command prints what the system is doing every five seconds. This is a good choice of printing interval since this is
how often some of the statistics are sampled in the system; others vary every second.
count Repeat the summary statistics count times. If count is omitted or zero, the output is repeated until an interrupt or quit
signal is received. From the terminal, these are commonly and respectively (see stty(1)).
Report on the number of forks
and the number of pages of virtual memory involved since boot-up.
Print the total number of several kinds of paging-related events
from the kernel structure that have occurred since boot-up or since was last executed with the option.
Clear all accumulators in the kernel
structure. This option is restricted to the super user.
If none of these options is given, displays a one-line summary of the virtual memory activity since boot-up or since the option was last
executed.
Column Descriptions
The column headings and the meaning of each column are:
Information about numbers of processes in various states.
In run queue
Blocked for resources (I/O, paging, etc.)
Runnable or short sleeper (< 20 secs) but swapped
Information about the usage of virtual and real memory.
Virtual pages are considered active if they belong to processes that are running or have run in the last 20 seconds.
Active virtual pages
Size of the free list
Information about page faults and paging activity.
These are averaged each five seconds, and given in units per second.
Page reclaims (without
Address translation faults (without
Processes swapped in (with
Processes swapped out (with
Pages paged in
Pages paged out
Pages freed per second
Anticipated short term memory shortfall
Pages scanned by clock algorithm, per second
Trap/interrupt rate averages per second over last 5 seconds.
Device interrupts per second (nonclock)
System calls per second
CPU context switch rate (switches/sec)
Breakdown of percentage usage of CPU time for the active processors
User time for normal and low priority processes
System time
CPU idle
EXAMPLES
The following examples show the output for various command options. For formatting purposes, some leading blanks have been deleted.
1. Display the default output.
2. Add the disk tranfer information to the default output.
3. Display the default output in 80-column format.
4. Replace the page reclaims and address translation faults with process swapping in the default output.
5. Display the default output twice at five-second intervals. Note that the headers are repeated.
6. Display the default output twice in 80-column format at five-second intervals. Note that the headers are repeated.
7. Display the default output and disk transfers twice in 80-column format at five-second intervals. Note that the headers repeated.
8. Display the number of forks and pages of virtual memory since boot-up.
9. Display the counts of paging-related events.
WARNINGS
Users of must not rely on the exact field widths and spacing of its output, as these will vary depending on the system, the release of HP-
UX, and the data to be displayed.
AUTHOR
was developed by the University of California, Berkeley and HP.
SEE ALSO iostat(1).
vmstat(1)