display system statistics
systat displays various system statistics
in a screen-oriented fashion using the
curses(3) screen display library.
systat is running, the
screen is divided into different areas. The top line displays the current
number of users, the three system load average figures over the last 1, 5,
and 15 minute intervals, and the system time. The bottom line of the screen
is reserved for user input and error messages. The information displayed in
the rest of the screen comprises a
view, and is the
main interface for displaying different types of system statistics. The
vmstat view is the default.
Certain information 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
The options are as follows:
- Display all lines.
- Raw, non-interactive mode. The default is to exit after two screen
updates, with statistics only ever displayed once. Useful for views such
cpu, where initial calculations are useless.
- Raw, non-interactive mode. The default is to exit after one screen update, with statistics displayed every update.
- Exit after count screen updates.
- Interactive mode.
- Resolve network addresses to names. This is the opposite of the
- Do not try to reverse map IP addresses. This is the default.
- Specifies the screen refresh time interval in seconds. This option is overridden by the final delay argument, if given. The default interval is 5 seconds.
- Specifies the maximum width of the output in raw, non-interactive mode.
- The view argument expects to be one of:
cpu. These displays can also be requested interactively and are described in full detail below. view may be abbreviated to the minimum unambiguous prefix; for example, “io” for “iostat”.
- The delay argument specifies the screen refresh time
interval in seconds. This is provided for backwards compatibility, and
overrides any interval specified with the
-sflag. The default interval is 5 seconds.
Certain characters cause immediate action by
systat. These are:
- Move the cursor to the command line and interpret the input line typed as a command. While entering a command the current character erase, word erase, and line kill characters may be used.
- Select the next ordering which sorts the rows according to a combination of columns. Available orderings depend on the view. Not all views support orderings.
- Reverse the selected ordering if supported by the view.
- Print numbers with thousand separators, where applicable.
- Jump to the beginning of the current view.
- Select the previous view.
- Jump to the end of the current view.
- Select the next view.
- Print the name of the current view being shown and the refresh interval.
- Refresh the screen.
- Scroll current view down by one line.
- Scroll current view up by one line.
- Scroll current view down by one page.
- Scroll current view up by one page.
The following commands are interpreted by the “global” command interpreter.
- Print the names of the available views on the command line.
systat. (This may be abbreviated to
- Stop refreshing the screen.
- Start (continue) refreshing the screen. If a second, numeric, argument is provided it is interpreted as a refresh interval (in seconds). Supplying only a number will set the refresh interval to this value.
view may be abbreviated to the minimum unambiguous prefix. The available views are:
- Display kernel
malloc(9) bucket statistics similar to the output of
- Display information about the average usage of each CPU, similar to the output provided by top(1).
- Display interface statistics. The “State” column has the
D]. ‘up’ and ‘dn’ represent whether the interface is up or down. ‘U’ and ‘D’ represent whether the interface is connected or not; in the case of carp(4) interfaces, whether the interface is in master or backup state, respectively.
Bchanges the counter view between bytes and bits. Pressing
bdisplays statistics as calculated from boot time.
rchanges the counters to show their totals as calculated between display refreshes.
tchanges the counters to show the average per second over the display refresh interval; this is the default.
- Display statistics about disk throughput. Statistics on disk throughput show, for each drive, data transferred in kilobytes, number of disk transactions performed, and time spent in disk accesses (in fractions of a second).
- Display kernel
malloc(9) type statistics similar to the output of
-m. Available orderings are:
- Display mbuf usage information from kernel pools and mbuf cluster pool statistics of each network interface.
- Display network connections. Each address is displayed numerically in the
format “host:port”. By default, network servers awaiting
requests are not displayed. It is also possible to have addresses
displayed symbolically, when possible, and limit the display to a set of
protocols (the minimum unambiguous prefix may be supplied):
- Toggle the displaying of server processes awaiting requests (this is
the equivalent of the
-aflag to netstat(1)).
- Display network addresses symbolically.
- Display network addresses numerically.
- Reset matching mechanisms to the default.
- Display only network connections using the indicated protocol.
- Display statistics about NFS client activity. Output resembles
- Display statistics about NFS server activity. Output resembles
- Display filter information about
pf(4), similar to the output of
- Display those processes resident in main memory and getting the largest portion of the processor. When less than 100% of the processor is scheduled to user processes, the remaining time is accounted to the “idle” process.
- Display kernel pool(9) statistics similar to the output of
-m. Available orderings are:
number of pages.
By default only the statistics of active pools are displayed but pressing
Achanges the view to show all of them.
- Display statistics about the active queues, similar to the output of
- Display pf rules statistics, similar to the output of
- Display the current values of available hardware sensors, in a format similar to that of sysctl(8).
- Display pf states statistics, similar to the output of
states. Available orderings are:
- 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 is 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 available.
- Take over the entire display and show a (rather crowded) compendium of
statistics related to virtual memory usage, process scheduling, device
interrupts, system name translation caching, disk I/O, etc. This view is
Below the top 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 amount of physical memory claimed by processes. The second column reports the same figure for virtual memory, that is, the amount of memory that would be needed if all processes were resident at the same time. Finally, the last column shows the amount of physical memory on the free list.
Below the memory display is a list of the average number of processes (over the last refresh interval) that are runnable (‘r’), 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 interrupt (shown as ‘
|’), system (shown as ‘
=’), user (shown as ‘
>’), nice (shown as ‘
-’), and idle time (shown as ‘
To the right of the Proc display are statistics about Context switches (“Csw”), Traps (“Trp”), Syscalls (“Sys”), Interrupts (“Int”), Soft interrupts (“Sof”), and Faults (“Flt”) which have occurred during the last refresh interval.
Below the CPU usage graph are statistics on name translations. It lists the number of names translated in the previous interval, 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.
At the bottom left is the disk usage display. It reports the number of seeks, transfers, number of kilobyte blocks transferred per second averaged over the refresh period of the display, and the time spent in disk accesses.
Under the date in the upper right hand quadrant are statistics 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 average 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 interval.
Running down the right hand side of the display is a breakdown 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 interrupted at least once since boot time are shown.
Below the Interrupts display are the average number of input and output packets per second for all interfaces over the last refresh interval.
Below the SWAPPING display and slightly to the left of the Interrupts display is a list of virtual memory statistics. The abbreviations are:
- process forks
- forks where parent waits
- forks where vmspace is shared
- fault had to wait on a page
- fault relock called
- fault relock is successful
- faults out of ram
- number of times fault clears "need copy"
- number of times fault promotes with copy
- fault promotes with zerofill
- number of times fault anon cow
- min number of free pages
- target number of free pages
- target number of inactive pages
- wired pages
- pages daemon freed since boot
- pages daemon scanned since boot
- number of zeroed pages
- number of kernel map entries
- Host names.
- pf(4) configuration.
- Port names.
fstat(1), kill(1), netstat(1), nfsstat(1), ps(1), top(1), iostat(8), pfctl(8), pstat(8), renice(8), sysctl(8), vmstat(8)
systat program first appeared in
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