SYSTAT(1) BSD Reference Manual SYSTAT(1)
systat - display system statistics on a crt
systat [-display] [refresh-interval]
Systat displays various system statistics in a screen oriented fashion
using the curses screen display library, curses(3).
While systat is running the screen is usually divided into two windows
(an exception is the vmstat display which uses the entire screen). The
upper window depicts the current system load average. The information
displayed in the lower window may vary, depending on user commands. The
last line on the screen is reserved for user input and error messages.
By default systat displays the processes getting the largest percentage
of the processor in the lower window. Other displays show swap space us-
age, disk I/O statistics (a la iostat(1)), virtual memory statistics (a
la vmstat(1)), network ``mbuf'' utilization, and network connections (a
Input is interpreted at two different levels. A ``global'' command in-
terpreter processes all keyboard input. If this command interpreter
fails to recognize a command, the input line is passed to a per-display
command interpreter. This allows each display to have certain display-
Command line options:
-display The - flag expects display to be one of: pigs, iostat,
swap, mbufs, vmstat or netstat. These displays can also
be requested interactively (without the ``-'') and are
described in full detail below.
refresh-interval The refresh-value specifies the screen refresh time in-
terval in seconds.
Certain characters cause immediate action by systat. These are
^L Refresh the screen.
^G Print the name of the current ``display'' being shown in the
lower window and the refresh interval.
^Z Stop systat.
: Move the cursor to the command line and interpret the input
line typed as a command. While entering a command the cur-
rent character erase, word erase, and line kill characters
may be used.
The following commands are interpreted by the ``global'' command inter-
help Print the names of the available displays on the command
load Print the load average over the past 1, 5, and 15 minutes on
the command line.
stop Stop refreshing the screen.
Start (continue) refreshing the screen. If a second, numer-
ic, argument is provided it is interpreted as a refresh in-
terval (in seconds). Supplying only a number will set the
refresh interval to this value.
quit Exit systat. (This may be abbreviated to q.)
The available displays are:
pigs Display, in the lower window, those processes resident in
main memory and getting the largest portion of the processor
(the default display). When less than 100% of the processor
is scheduled to user processes, the remaining time is ac-
counted to the ``idle'' process.
iostat Display, in the lower window, statistics about processor use
and disk throughput. Statistics on processor use appear as
bar graphs of the amount of time executing in user mode
(``user''), in user mode running low priority processes
(``nice''), in system mode (``system''), and idle (``idle'').
Statistics on disk throughput show, for each drive, kilobytes
of data transferred, number of disk transactions performed,
and average seek time (in milliseconds). This information
may be displayed as bar graphs or as rows of numbers which
scroll downward. Bar graphs are shown by default;
The following commands are specific to the iostat display;
the minimum unambiguous prefix may be supplied.
numbers Show the disk I/O statistics in numeric form.
Values are displayed in numeric columns which
bars Show the disk I/O statistics in bar graph form
msps Toggle the display of average seek time (the de-
fault is to not display seek times).
swap Show information about swap space usage on all the swap areas
compiled into the kernel. The first column is the device
name of the partition. The next column is the total space
available in the partition. The Used column indicates the
total blocks used so far; the graph shows the percentage of
space in use on each partition. If there are more than one
swap partition in use, a total line is also shown. Areas
known to the kernel, but not in use are shown as not avail-
mbufs Display, in the lower window, the number of mbufs allocated
for particular uses, i.e. data, socket structures, etc.
vmstat Take over the entire display and show a (rather crowded) com-
pendium of statistics related to virtual memory usage, pro-
cess scheduling, device interrupts, system name translation
cacheing, disk I/O etc.
The upper left quadrant of the screen shows the number of
users logged in and the load average over the last one, five,
and fifteen minute intervals. Below this line are statistics
on memory utilization. The first row of the table reports
memory usage only among active processes, that is processes
that have run in the previous twenty seconds. The second row
reports on memory usage of all processes. The first column
reports on the number of physical pages claimed by processes.
The second column reports the number of physical pages that
are devoted to read only text pages. The third and fourth
columns report the same two figures for virtual pages, that
is the number of pages that would be needed if all processes
had all of their pages. Finally the last column shows the
number of physical pages on the free list.
Below the memory display is the disk usage display. It re-
ports the number of seeks, transfers, and number of kilobyte
blocks transferred per second averaged over the refresh peri-
od of the display (by default, five seconds). For some disks
it also reports the average milliseconds per seek. Note that
the system only keeps statistics on at most four disks.
Below the disk display is a list of the average number of
processes (over the last refresh interval) that are runnable
(`r'), in page wait (`p'), in disk wait other than paging
(`d'), sleeping (`s'), and swapped out but desiring to run
(`w'). Below the queue length listing is a numerical listing
and a bar graph showing the amount of system (shown as `='),
user (shown as `>'), nice (shown as `-'), and idle time
(shown as ` ').
At the bottom left are statistics on name translations. It
lists the number of names translated in the previous inter-
val, the number and percentage of the translations that were
handled by the system wide name translation cache, and the
number and percentage of the translations that were handled
by the per process name translation cache.
Under the date in the upper right hand quadrant are statis-
tics on paging and swapping activity. The first two columns
report the average number of pages brought in and out per
second over the last refresh interval due to page faults and
the paging daemon. The third and fourth columns report the
average number of pages brought in and out per second over
the last refresh interval due to swap requests initiated by
the scheduler. The first row of the display shows the aver-
age number of disk transfers per second over the last refresh
interval; the second row of the display shows the average
number of pages transferred per second over the last refresh
Below the paging statistics is a line listing the average
number of total reclaims ('Rec'), intransit blocking page
faults (`It'), swap text pages found in free list (`F/S'),
file system text pages found in free list (`F/F'), reclaims
from free list pages freed by the clock daemon (`Fre'), and
sequential process pages freed (`SFr') per second over the
Below this line are statistics on the average number of zero
filled pages (`zf') and demand filled text pages (`xf') per
second over the refresh period. The first row indicates the
number of requests that were resolved, the second row shows
the number that were set up, and the last row shows the per-
centage of setup requests that were actually used. Note that
this percentage is usually less than 100%, however it may ex-
ceed 100% if a large number of requests are actually used
long after they were set up during a period when no new pages
are being set up. Thus this figure is most interesting when
observed over a long time period, such as from boot time (see
below on getting such a display).
Below the page fill statistics is a column that lists the av-
erage number of context switches (`Csw'), traps (`Trp'; in-
cludes page faults), system calls (`Sys'), interrupts
(`Int'), characters output to DZ ports using pseudo-DMA
(`Pdm'), network software interrupts (`Sof'), page faults
(`Flt'), pages scanned by the page daemon (`Scn'), and revo-
lutions of the page daemon's hand (`Rev') per second over the
Running down the right hand side of the display is a break-
down of the interrupts being handled by the system. At the
top of the list is the total interrupts per second over the
time interval. The rest of the column breaks down the total
on a device by device basis. Only devices that have inter-
rupted at least once since boot time are shown.
The following commands are specific to the vmstat display;
the minimum unambiguous prefix may be supplied.
boot Display cumulative statistics since the system
run Display statistics as a running total from the
point this command is given.
time Display statistics averaged over the refresh
interval (the default).
zero Reset running statistics to zero.
netstat Display, in the lower window, network connections. By de-
fault, network servers awaiting requests are not displayed.
Each address is displayed in the format ``host.port'', with
each shown symbolically, when possible. It is possible to
have addresses displayed numerically, limit the display to a
set of ports, hosts, and/or protocols (the minimum unambigu-
ous prefix may be supplied):
all Toggle the displaying of server processes
awaiting requests (this is the equivalent of
the -a flag to netstat 1).
numbers Display network addresses numerically.
names Display network addresses symbolically.
protocol Display only network connections using the in-
dicated protocol (currently either ``tcp'' or
Do not display information about connections
associated with the specified hosts or ports.
Hosts and ports may be specified by name
(``vangogh'', ``ftp''), or numerically. Host
addresses use the Internet dot notation
(``220.127.116.11''). Multiple items may be speci-
fied with a single command by separating them
Display information about the connections asso-
ciated with the specified hosts or ports. As
for ignore, [items] may be names or numbers.
Show, on the command line, the currently se-
lected protocols, hosts, and ports. Hosts and
ports which are being ignored are prefixed with
a `!'. If ports or hosts is supplied as an ar-
gument to show, then only the requested infor-
mation will be displayed.
reset Reset the port, host, and protocol matching
mechanisms to the default (any protocol, port,
Commands to switch between displays may be abbreviated to the minimum un-
ambiguous prefix; for example, ``io'' for ``iostat''. Certain informa-
tion may be discarded when the screen size is insufficient for display.
For example, on a machine with 10 drives the iostat bar graph displays
only 3 drives on a 24 line terminal. When a bar graph would overflow the
allotted screen space it is truncated and the actual value is printed
``over top'' of the bar.
The following commands are common to each display which shows information
about disk drives. These commands are used to select a set of drives to
report on, should your system have more drives configured than can nor-
mally be displayed on the screen.
ignore [drives] Do not display information about the drives indi-
cated. Multiple drives may be specified, sepa-
rated by spaces.
display [drives] Display information about the drives indicated.
Multiple drives may be specified, separated by
/vmunix For the namelist.
/dev/kmem For information in main memory.
/dev/drum For information about swapped out processes.
/etc/hosts For host names.
/etc/networks For network names.
/etc/services For port names.
The systat program appeared in 4.3BSD.
Takes 2-10 percent of the cpu. Certain displays presume a minimum of 80
characters per line. The vmstat display looks out of place because it is
(it was added in as a separate display rather than created as a new pro-
4.3 Berkeley Distribution December 30, 1993 5