atop

ATOP(1)                      General Commands Manual                     ATOP(1)



NAME
       atop - Advanced System & Process Monitor

SYNOPSIS
       Interactive usage:

       atop [-g|-m|-d|-n|-u|-p|-s|-c|-v|-o|-y] [-C|-M|-D|-N|-A] [-afF1x] [-L
       linelen] [-Plabel[,label]...]  [ interval [ samples ]]

       Writing and reading raw logfiles:

       atop -w rawfile [-a] [-S] [ interval [ samples ]]
       atop -r [ rawfile ] [-b hh:mm ] [-e hh:mm ]
       [-g|-m|-d|-n|-u|-p|-s|-c|-v|-o|-y] [-C|-M|-D|-N|-A] [-fF1x] [-L linelen]
       [-Plabel[,label]...]

DESCRIPTION
       The program atop is an interactive monitor to view the load on a Linux
       system.  It shows the occupation of the most critical hardware resources
       (from a performance point of view) on system level, i.e. cpu, memory,
       disk and network.
       It also shows which processes are responsible for the indicated load with
       respect to cpu- and memory load on process level.  Disk load is shown per
       process if "storage accounting" is active in the kernel.  Network load is
       shown per process if the kernel module `netatop' has been installed.

       Every interval (default: 10 seconds) information is shown about the
       resource occupation on system level (cpu, memory, disks and network
       layers), followed by a list of processes which have been active during
       the last interval (note that all processes that were unchanged during the
       last interval are not shown, unless the key 'a' has been pressed).  If
       the list of active processes does not entirely fit on the screen, only
       the top of the list is shown (sorted in order of activity).
       The intervals are repeated till the number of samples (specified as
       command argument) is reached, or till the key 'q' is pressed in
       interactive mode.

       When atop is started, it checks whether the standard output channel is
       connected to a screen, or to a file/pipe. In the first case it produces
       screen control codes (via the ncurses library) and behaves interactively;
       in the second case it produces flat ASCII-output.

       In interactive mode, the output of atop scales dynamically to the current
       dimensions of the screen/window.
       If the window is resized horizontally, columns will be added or removed
       automatically. For this purpose, every column has a particular weight.
       The columns with the highest weights that fit within the current width
       will be shown.
       If the window is resized vertically, lines of the process/thread list
       will be added or removed automatically.

       Furthermore in interactive mode the output of atop can be controlled by
       pressing particular keys.  However it is also possible to specify such
       key as flag on the command line. In that case atop switches to the
       indicated mode on beforehand; this mode can be modified again
       interactively. Specifying such key as flag is especially useful when
       running atop with output to a pipe or file (non-interactively).  These
       flags are the same as the keys that can be pressed in interactive mode
       (see section INTERACTIVE COMMANDS).
       Additional flags are available to support storage of atop-data in raw
       format (see section RAW DATA STORAGE).

PROCESS ACCOUNTING
       When atop is started, it activates the process accounting mechanism in
       the kernel. This forces the kernel to write a record with accounting
       information to the accounting file whenever a process ends.  With every
       interval, atop reads the kernel administration concerning the running
       processes and the accounting records on disk concerning the exited
       processes.  In this way atop also shows the remaining activity of a
       process during the interval in which it is finished.
       Whenever the last incarnation of atop stops (either by pressing `q' or by
       `kill -15'), it deactivates the process accounting mechanism again.
       Therefore you should never terminate atop by `kill -9', because then it
       has no chance to stop process accounting.  As a result the accounting
       file may consume a lot of disk space after a while.
       To avoid that the process accounting file consumes too much disk space,
       atop verifies at the end of every sample if the size of the process
       accounting file exceeds 200 MiB and if this atop process is the only one
       that is currently using the file.  In that case the file is truncated to
       a size of zero again.
       When during one interval a lot of processes have finished, atop might
       grow tremendously in memory when reading all process accounting records
       at the end of the interval. To avoid such excessive growth, atop will
       never read more than 50 MiB with process information from the process
       accounting file per interval (approx. 72000 finished processes).  In
       interactive mode a warning is given whenever processes have been skipped
       for this reason.

       With the environment variable ATOPACCT the name of a specific process
       accounting file can be specified (accounting should have been activated
       on beforehand). When this environment variable is present but its
       contents is empty, process accounting will not be used at all.

       Notice that root-privileges are required to switch on process accounting
       in the kernel. You can start atop as root or specify setuid-root
       privileges to the executable file.  In the latter case, atop switches on
       process accounting and immediately drops the root-privileges again.
       If atop does not run with root-privileges, it does not show information
       about finished processes. It indicates this situation with the message
       message `no procacct` in the top-right corner (instead of the counter
       that shows the number of exited processes).

COLORS
       For the resource consumption on system level, atop uses colors to
       indicate that a critical occupation percentage has been (almost) reached.
       A critical occupation percentage means that is likely that this load
       causes a noticable negative performance influence for applications using
       this resource. The critical percentage depends on the type of resource:
       e.g. the performance influence of a disk with a busy percentage of 80%
       might be more noticable for applications/user than a CPU with a busy
       percentage of 90%.
       Currently atop uses the following default values to calculate a weighted
       percentage per resource:

        Processor
            A busy percentage of 90% or higher is considered `critical'.

        Disk
            A busy percentage of 70% or higher is considered `critical'.

        Network
            A busy percentage of 90% or higher for the load of an interface is
            considered `critical'.

        Memory
            An occupation percentage of 90% is considered `critical'.  Notice
            that this occupation percentage is the accumulated memory
            consumption of the kernel (including slab) and all processes; the
            memory for the page cache (`cache' and `buff' in the MEM-line) and
            the reclaimable part of the slab (`slrec`) is not implied!
            If the number of pages swapped out (`swout' in the PAG-line) is
            larger than 10 per second, the memory resource is considered
            `critical'.  A value of at least 1 per second is considered `almost
            critical'.
            If the committed virtual memory exceeds the limit (`vmcom' and
            `vmlim' in the SWP-line), the SWP-line is colored due to
            overcommitting the system.

        Swap
            An occupation percentage of 80% is considered `critical' because
            swap space might be completely exhausted in the near future; it is
            not critical from a performance point-of-view.

       These default values can be modified in the configuration file (see
       separate man-page of atoprc).

       When a resource exceeds its critical occupation percentage, the
       concerning values in the screen line are colored red.
       When a resource exceeded (default) 80% of its critical percentage (so it
       is almost critical), the concerning values in the screen line are colored
       cyan. This `almost critical percentage' (one value for all resources) can
       be modified in the configuration file (see separate man-page of atoprc).

       With the key 'x' (or flag -x), the use of colors can be suppressed.

NETATOP MODULE
       When the netatop kernel module is loaded, atop verifies for every process
       or thread if network counters are gathered by this module. If so, the
       number of sent and received packets are per process/thread are shown in
       th generic screen. Besides, detailed counters can be requested by
       pressing the `n' key.
       When the netatopd daemon is running as well, atop also reads the network
       counters of exited processes that are logged by this daemon (comparable
       with process accounting).

       More information about the optional netatop kernel module and the
       netatopd daemon can be found in the concerning man-pages and on the
       website mentioned at the end of this manual page.

INTERACTIVE COMMANDS
       When running atop interactively (no output redirection), keys can be
       pressed to control the output. In general, lower case keys can be used to
       show other information for the active processes and upper case keys can
       be used to influence the sort order of the active process/thread list.

       g    Show generic output (default).

            Per process the following fields are shown in case of a window-width
            of 80 positions: process-id, cpu consumption during the last
            interval in system- and user mode, the virtual and resident memory
            growth of the process.

            The subsequent columns depend on the used kernel:
            When the kernel supports "storage accounting" (>= 2.6.20), the data
            transfer for read/write on disk, the status and exit code are shown
            for each process.  When the kernel does not support "storage
            accounting", the username, number of threads in the thread group,
            the status and exit code are shown.
            When the kernel module 'netatop' is loaded, the data transfer for
            send/receive of network packets is shown for each process.
            The last columns contain the state, the occupation percentage for
            the chosen resource (default: cpu) and the process name.

            When more than 80 positions are available, other information is
            added.

       m    Show memory related output.

            Per process the following fields are shown in case of a window-width
            of 80 positions: process-id, minor and major memory faults, size of
            virtual shared text, total virtual process size, total resident
            process size, virtual and resident growth during last interval,
            memory occupation percentage and process name.

            When more than 80 positions are available, other information is
            added.

       d    Show disk-related output.

            When "storage accounting" is active in the kernel, the following
            fields are shown: process-id, amount of data read from disk, amount
            of data written to disk, amount of data that was written but has
            been withdrawn again (WCANCL), disk occupation percentage and
            process name.

       n    Show network related output.

            Per process the following fields are shown in case of a window-width
            of 80 positions: process-id, thread-id, total bandwidth for received
            packets, total bandwidth for sent packets, number of received TCP
            packets with the average size per packet (in bytes), number of sent
            TCP packets with the average size per packet (in bytes), number of
            received UDP packets with the average size per packet (in bytes),
            number of sent UDP packets with the average size per packet (in
            bytes), the network occupation percentage and process name.
            This information can only be shown when kernel module `netatop' is
            installed.

            When more than 80 positions are available, other information is
            added.

       s    Show scheduling characteristics.

            Per process the following fields are shown in case of a window-width
            of 80 positions: process-id, number of threads in state 'running'
            (R), number of threads in state 'interruptible sleeping' (S), number
            of threads in state 'uninterruptible sleeping' (D), scheduling
            policy (normal timesharing, realtime round-robin, realtime fifo),
            nice value, priority, realtime priority, current processor, status,
            exit code, state, the occupation percentage for the chosen resource
            and the process name.

            When more than 80 positions are available, other information is
            added.

       v    Show various process characteristics.

            Per process the following fields are shown in case of a window-width
            of 80 positions: process-id, user name and group, start date and
            time, status (e.g. exit code if the process has finished), state,
            the occupation percentage for the chosen resource and the process
            name.

            When more than 80 positions are available, other information is
            added.

       c    Show the command line of the process.

            Per process the following fields are shown: process-id, the
            occupation percentage for the chosen resource and the command line
            including arguments.

       o    Show the user-defined line of the process.

            In the configuration file the keyword ownprocline can be specified
            with the description of a user-defined output-line.
            Refer to the man-page of atoprc for a detailed description.

       y    Show the individual threads within a process (toggle).

            Single-threaded processes are still shown as one line.
            For multi-threaded processes, one line represents the process while
            additional lines show the activity per individual thread (in a
            different color). Depending on the option 'a' (all or active
            toggle), all threads are shown or only the threads that were active
            during the last interval.
            Whether this key is active or not can be seen in the header line.

       u    Show the process activity accumulated per user.

            Per user the following fields are shown: number of processes active
            or terminated during last interval (or in total if combined with
            command `a'), accumulated cpu consumption during last interval in
            system- and user mode, the current virtual and resident memory space
            consumed by active processes (or all processes of the user if
            combined with command `a').
            When "storage accounting" is active in the kernel, the accumulated
            read- and write throughput on disk is shown.  When the kernel module
            `netatop' has been installed, the number of received and sent
            network packets are shown.
            The last columns contain the accumulated occupation percentage for
            the chosen resource (default: cpu) and the user name.

       p    Show the process activity accumulated per program (i.e. process
            name).

            Per program the following fields are shown: number of processes
            active or terminated during last interval (or in total if combined
            with command `a'), accumulated cpu consumption during last interval
            in system- and user mode, the current virtual and resident memory
            space consumed by active processes (or all processes of the user if
            combined with command `a').
            When "storage accounting" is active in the kernel, the accumulated
            read- and write throughput on disk is shown.  When the kernel module
            `netatop' has been installed, the number of received and sent
            network packets are shown.
            The last columns contain the accumulated occupation percentage for
            the chosen resource (default: cpu) and the program name.

       C    Sort the current list in the order of cpu consumption (default).
            The one-but-last column changes to ``CPU''.

       M    Sort the current list in the order of resident memory consumption.
            The one-but-last column changes to ``MEM''.

       D    Sort the current list in the order of disk accesses issued.  The
            one-but-last column changes to ``DSK''.

       N    Sort the current list in the order of network bandwidth (received
            and transmitted).  The one-but-last column changes to ``NET''.

       A    Sort the current list automatically in the order of the most busy
            system resource during this interval.  The one-but-last column shows
            either ``ACPU'', ``AMEM'', ``ADSK'' or ``ANET'' (the preceding 'A'
            indicates automatic sorting-order).  The most busy resource is
            determined by comparing the weighted busy-percentages of the system
            resources, as described earlier in the section COLORS.
            This option remains valid until another sorting-order is explicitly
            selected again.
            A sorting-order for disk is only possible when "storage accounting"
            is active.  A sorting-order for network is only possible when the
            kernel module `netatop' is loaded.

       Miscellaneous interactive commands:

       ?    Request for help information (also the key 'h' can be pressed).

       V    Request for version information (version number and date).

       x    Suppress colors to highlight critical resources (toggle).
            Whether this key is active or not can be seen in the header line.

       z    The pause key can be used to freeze the current situation in order
            to investigate the output on the screen. While atop is paused, the
            keys described above can be pressed to show other information about
            the current list of processes.  Whenever the pause key is pressed
            again, atop will continue with a next sample.

       i    Modify the interval timer (default: 10 seconds). If an interval
            timer of 0 is entered, the interval timer is switched off. In that
            case a new sample can only be triggered manually by pressing the key
            't'.

       t    Trigger a new sample manually. This key can be pressed if the
            current sample should be finished before the timer has exceeded, or
            if no timer is set at all (interval timer defined as 0). In the
            latter case atop can be used as a stopwatch to measure the load
            being caused by a particular application transaction, without
            knowing on beforehand how many seconds this transaction will last.

            When viewing the contents of a raw file, this key can be used to
            show the next sample from the file.

       T    When viewing the contents of a raw file, this key can be used to
            show the previous sample from the file.

       b    When viewing the contents of a raw file, this key can be used to
            branch to a certain timestamp within the file (either forward or
            backward).

       r    Reset all counters to zero to see the system and process activity
            since boot again.

            When viewing the contents of a raw file, this key can be used to
            rewind to the beginning of the file again.

       U    Specify a search string for specific user names as a regular
            expression.  From now on, only (active) processes will be shown from
            a user which matches the regular expression.  The system statistics
            are still system wide.  If the Enter-key is pressed without
            specifying a name, active processes of all users will be shown
            again.
            Whether this key is active or not can be seen in the header line.

       P    Specify a search string for specific process names as a regular
            expression.  From now on, only processes will be shown with a name
            which matches the regular expression.  The system statistics are
            still system wide.  If the Enter-key is pressed without specifying a
            name, all active processes will be shown again.
            Whether this key is active or not can be seen in the header line.

       S    Specify search strings for specific logical volume names, specific
            disk names and specific network interface names. All search strings
            are interpreted as a regular expressions.  From now on, only those
            system resources are shown that match the concerning regular
            expression.  If the Enter-key is pressed without specifying a search
            string, all (active) system resources of that type will be shown
            again.
            Whether this key is active or not can be seen in the header line.

       a    The `all/active' key can be used to toggle between only
            showing/accumulating the processes that were active during the last
            interval (default) or showing/accumulating all processes.
            Whether this key is active or not can be seen in the header line.

       f    Show a fixed (maximum) number of header lines for system resources
            (toggle).  By default only the lines are shown about system
            resources (CPUs, paging, logical volumes, disks, network interfaces)
            that really have been active during the last interval.  With this
            key you can force atop to show lines of inactive resources as well.
            Whether this key is active or not can be seen in the header line.

       F    Suppress sorting of system resources (toggle).  By default system
            resources (CPUs, logical volumes, disks, network interfaces) are
            sorted on utilization.
            Whether this key is active or not can be seen in the header line.

       1    Show relevant counters as an average per second (in the format
            `..../s') instead of as a total during the interval (toggle).
            Whether this key is active or not can be seen in the header line.

       l    Limit the number of system level lines for the counters per-cpu, the
            active disks and the network interfaces.  By default lines are shown
            of all CPUs, disks and network interfaces which have been active
            during the last interval.  Limiting these lines can be useful on
            systems with huge number CPUs, disks or interfaces in order to be
            able to run atop on a screen/window with e.g. only 24 lines.
            For all mentioned resources the maximum number of lines can be
            specified interactively. When using the flag -l the maximum number
            of per-cpu lines is set to 0, the maximum number of disk lines to 5
            and the maximum number of interface lines to 3.  These values can be
            modified again in interactive mode.

       k    Send a signal to an active process (a.k.a. kill a process).

       q    Quit the program.

       PgDn Show the next page of the process/thread list.
            With the arrow-down key the list can be scrolled downwards with
            single lines.

       ^F   Show the next page of the process/thread list (forward).
            With the arrow-down key the list can be scrolled downwards with
            single lines.

       PgUp Show the previous page of the process/thread list.
            With the arrow-up key the list can be scrolled upwards with single
            lines.

       ^B   Show the previous page of the process/thread list (backward).
            With the arrow-up key the list can be scrolled upwards with single
            lines.

       ^L   Redraw the screen.

RAW DATA STORAGE
       In order to store system- and process level statistics for long-term
       analysis (e.g. to check the system load and the active processes running
       yesterday between 3:00 and 4:00 PM), atop can store the system- and
       process level statistics in compressed binary format in a raw file with
       the flag -w followed by the filename.  If this file already exists and is
       recognized as a raw data file, atop will append new samples to the file
       (starting with a sample which reflects the activity since boot); if the
       file does not exist, it will be created.
       By default only processes which have been active during the interval are
       stored in the raw file. When the flag -a is specified, all processes will
       be stored.
       The interval (default: 10 seconds) and number of samples (default:
       infinite) can be passed as last arguments. Instead of the number of
       samples, the flag -S can be used to indicate that atop should finish
       anyhow before midnight.

       A raw file can be read and visualized again with the flag -r followed by
       the filename. If no filename is specified, the file
       /var/log/atop/atop_YYYYMMDD is opened for input (where YYYYMMDD are
       digits representing the current date).  If a filename is specified in the
       format YYYYMMDD (representing any valid date), the file
       /var/log/atop/atop_YYYYMMDD is opened.  If a filename with the symbolic
       name y is specified, yesterday's daily logfile is opened (this can be
       repeated so 'yyyy' indicates the logfile of four days ago).
       The samples from the file can be viewed interactively by using the key
       't' to show the next sample, the key 'T' to show the previous sample, the
       key 'b' to branch to a particular time or the key 'r' to rewind to the
       begin of the file.
       When output is redirected to a file or pipe, atop prints all samples in
       plain ASCII. The default line length is 80 characters in that case; with
       the flag -L followed by an alternate line length, more (or less) columns
       will be shown.
       With the flag -b (begin time) and/or -e (end time) followed by a time
       argument of the form HH:MM, a certain time period within the raw file can
       be selected.

       When atop is installed, the script atop.daily is stored in the /etc/atop
       directory.  This scripts takes care that atop is activated every day at
       midnight to write compressed binary data to the file
       /var/log/atop/atop_YYYYMMDD with an interval of 10 minutes.
       Furthermore the script removes all raw files which are older than four
       weeks.
       The script is activated via the cron daemon using the file
       /etc/cron.d/atop with the contents
               0 0 * * * root /etc/atop/atop.daily

       When the RPM `psacct' is installed, the process accounting is
       automatically restarted via the logrotate mechanism. The file
       /etc/logrotate.d/psaccs_atop takes care that atop is finished just before
       the rotation of the process accounting file and the file
       /etc/logrotate.d/psaccu_atop takes care that atop is restarted again
       after the rotation.  When the RPM `psacct' is not installed, these
       logrotate-files have no effect.

OUTPUT DESCRIPTION
       The first sample shows the system level activity since boot (the elapsed
       time in the header shows the time since boot).  Note that particular
       counters could have reached their maximum value (several times) and
       started by zero again, so do not rely on these figures.

       For every sample atop first shows the lines related to system level
       activity. If a particular system resource has not been used during the
       interval, the entire line related to this resource is suppressed. So the
       number of system level lines may vary for each sample.
       After that a list is shown of processes which have been active during the
       last interval. This list is by default sorted on cpu consumption, but
       this order can be changed by the keys which are previously described.

       If values have to be shown by atop which do not fit in the column width,
       another format is used. If e.g. a cpu-consumption of 233216 milliseconds
       should be shown in a column width of 4 positions, it is shown as `233s'
       (in seconds).  For large memory figures, another unit is chosen if the
       value does not fit (Mb instead of Kb, Gb instead of Mb, Tb instead of Gb,
       ...).  For other values, a kind of exponent notation is used (value
       123456789 shown in a column of 5 positions gives 123e6).

OUTPUT DESCRIPTION - SYSTEM LEVEL
       The system level information consists of the following output lines:

       PRC  Process and thread level totals.
            This line contains the total cpu time consumed in system mode
            (`sys') and in user mode (`user'), the total number of processes
            present at this moment (`#proc'), the total number of threads
            present at this moment in state `running' (`#trun'), `sleeping
            interruptible' (`#tslpi') and `sleeping uninterruptible' (`#tslpu'),
            the number of zombie processes (`#zombie'), the number of clone
            system calls (`clones'), and the number of processes that ended
            during the interval (`#exit') when process accounting is used.
            Instead of `#exit` the last column may indicate that process
            accounting could not be activated (`no procacct`).
            If the screen-width does not allow all of these counters, only a
            relevant subset is shown.

       CPU  CPU utilization.
            At least one line is shown for the total occupation of all CPUs
            together.
            In case of a multi-processor system, an additional line is shown for
            every individual processor (with `cpu' in lower case), sorted on
            activity. Inactive CPUs will not be shown by default.  The lines
            showing the per-cpu occupation contain the cpu number in the last
            field.

            Every line contains the percentage of cpu time spent in kernel mode
            by all active processes (`sys'), the percentage of cpu time consumed
            in user mode (`user') for all active processes (including processes
            running with a nice value larger than zero), the percentage of cpu
            time spent for interrupt handling (`irq') including softirq, the
            percentage of unused cpu time while no processes were waiting for
            disk-I/O (`idle'), and the percentage of unused cpu time while at
            least one process was waiting for disk-I/O (`wait').
            In case of per-cpu occupation, the last column shows the cpu number
            and the wait percentage (`w') for that cpu.  The number of lines
            showing the per-cpu occupation can be limited.

            For virtual machines the steal-percentage is shown (`steal'),
            reflecting the percentage of cpu time stolen by other virtual
            machines running on the same hardware.
            For physical machines hosting one or more virtual machines, the
            guest-percentage is shown (`guest'), reflecting the percentage of
            cpu time used by the virtual machines.

            In case of frequency-scaling, all previously mentioned CPU-
            percentages are relative to the used scaling of the CPU during the
            interval.  If a CPU has been active for e.g. 50% in user mode during
            the interval while the frequency-scaling of that CPU was 40%, only
            20% of the full capacity of the CPU has been used in user mode.
            In case that the kernel module `cpufreq_stats' is active (after
            issueing `modprobe cpufreq_stats'), the average frequency (`avgf')
            and the average scaling percentage (`avgscal') is shown. Otherwise
            the current frequency (`curf') and the current scaling percentage
            (`curscal') is shown at the moment that the sample is taken.

            If the screen-width does not allow all of these counters, only a
            relevant subset is shown.

       CPL  CPU load information.
            This line contains the load average figures reflecting the number of
            threads that are available to run on a CPU (i.e. part of the
            runqueue) or that are waiting for disk I/O. These figures are
            averaged over 1 (`avg1'), 5 (`avg5') and 15 (`avg15') minutes.
            Furthermore the number of context switches (`csw'), the number of
            serviced interrupts (`intr') and the number of available CPUs are
            shown.

            If the screen-width does not allow all of these counters, only a
            relevant subset is shown.

       MEM  Memory occupation.
            This line contains the total amount of physical memory (`tot'), the
            amount of memory which is currently free (`free'), the amount of
            memory in use as page cache including the total resident shared
            memory (`cache'), the amount of memory within the page cache that
            has to be flushed to disk (`dirty'), the amount of memory used for
            filesystem meta data (`buff'), the amount of memory being used for
            kernel mallocs (`slab'), the amount of slab memory that is
            reclaimable (`slrec'), the resident size of shared memory including
            tmpfs (`shmem`), the resident size of shared memory (`shrss`) and
            the amount of shared memory that is currently swapped (`shswp`).

            If the screen-width does not allow all of these counters, only a
            relevant subset is shown.

       SWP  Swap occupation and overcommit info.
            This line contains the total amount of swap space on disk (`tot')
            and the amount of free swap space (`free').
            Furthermore the committed virtual memory space (`vmcom') and the
            maximum limit of the committed space (`vmlim', which is by default
            swap size plus 50% of memory size) is shown.  The committed space is
            the reserved virtual space for all allocations of private memory
            space for processes. The kernel only verifies whether the committed
            space exceeds the limit if strict overcommit handling is configured
            (vm.overcommit_memory is 2).

       PAG  Paging frequency.
            This line contains the number of scanned pages (`scan') due to the
            fact that free memory drops below a particular threshold and the
            number times that the kernel tries to reclaim pages due to an urgent
            need (`stall').
            Also the number of memory pages the system read from swap space
            (`swin') and the number of memory pages the system wrote to swap
            space (`swout') are shown.

       LVM/MDD/DSK
            Logical volume/multiple device/disk utilization.
            Per active unit one line is produced, sorted on unit activity.  Such
            line shows the name (e.g. VolGroup00-lvtmp for a logical volume or
            sda for a hard disk), the busy percentage i.e. the portion of time
            that the unit was busy handling requests (`busy'), the number of
            read requests issued (`read'), the number of write requests issued
            (`write'), the number of KiBytes per read (`KiB/r'), the number of
            KiBytes per write (`KiB/w'), the number of MiBytes per second
            throughput for reads (`MBr/s'), the number of MiBytes per second
            throughput for writes (`MBw/s'), the average queue depth (`avq') and
            the average number of milliseconds needed by a request (`avio') for
            seek, latency and data transfer.
            If the screen-width does not allow all of these counters, only a
            relevant subset is shown.

            The number of lines showing the units can be limited per class (LVM,
            MDD or DSK) with the 'l' key or statically (see separate man-page of
            atoprc).  By specifying the value 0 for a particular class, no lines
            will be shown any more for that class.

       NET  Network utilization (TCP/IP).
            One line is shown for activity of the transport layer (TCP and UDP),
            one line for the IP layer and one line per active interface.
            For the transport layer, counters are shown concerning the number of
            received TCP segments including those received in error (`tcpi'),
            the number of transmitted TCP segments excluding those containing
            only retransmitted octets (`tcpo'), the number of UDP datagrams
            received (`udpi'), the number of UDP datagrams transmitted (`udpo'),
            the number of active TCP opens (`tcpao'), the number of passive TCP
            opens (`tcppo'), the number of TCP output retransmissions (`tcprs'),
            the number of TCP input errors (`tcpie'), the number of TCP output
            resets (`tcpie'), the number of TCP output retransmissions
            (`tcpor'), the number of UDP no ports (`udpnp'), and the number of
            UDP input errors (`tcpie').
            If the screen-width does not allow all of these counters, only a
            relevant subset is shown.
            These counters are related to IPv4 and IPv6 combined.

            For the IP layer, counters are shown concerning the number of IP
            datagrams received from interfaces, including those received in
            error (`ipi'), the number of IP datagrams that local higher-layer
            protocols offered for transmission (`ipo'), the number of received
            IP datagrams which were forwarded to other interfaces (`ipfrw'), the
            number of IP datagrams which were delivered to local higher-layer
            protocols (`deliv'), the number of received ICMP datagrams
            (`icmpi'), and the number of transmitted ICMP datagrams (`icmpo').
            If the screen-width does not allow all of these counters, only a
            relevant subset is shown.
            These counters are related to IPv4 and IPv6 combined.

            For every active network interface one line is shown, sorted on the
            interface activity.  Such line shows the name of the interface and
            its busy percentage in the first column.  The busy percentage for
            half duplex is determined by comparing the interface speed with the
            number of bits transmitted and received per second; for full duplex
            the interface speed is compared with the highest of either the
            transmitted or the received bits.  When the interface speed can not
            be determined (e.g. for the loopback interface), `---' is shown
            instead of the percentage.
            Furthermore the number of received packets (`pcki'), the number of
            transmitted packets (`pcko'), the effective amount of bits received
            per second (`si'), the effective amount of bits transmitted per
            second (`so'), the number of collisions (`coll'), the number of
            received multicast packets (`mlti'), the number of errors while
            receiving a packet (`erri'), the number of errors while transmitting
            a packet (`erro'), the number of received packets dropped (`drpi'),
            and the number of transmitted packets dropped (`drpo').
            If the screen-width does not allow all of these counters, only a
            relevant subset is shown.
            The number of lines showing the network interfaces can be limited.

OUTPUT DESCRIPTION - PROCESS LEVEL
       Following the system level information, the processes are shown from
       which the resource utilization has changed during the last interval.
       These processes might have used cpu time or issued disk- or network
       requests. However a process is also shown if part of it has been paged
       out due to lack of memory (while the process itself was in sleep state).

       Per process the following fields may be shown (in alphabetical order),
       depending on the current output mode as described in the section
       INTERACTIVE COMMANDS and depending on the current width of your window:

       AVGRSZ   The average size of one read-action on disk.

       AVGWSZ   The average size of one write-action on disk.

       BANDWI   Total bandwidth for received TCP and UDP packets consumed by
                this process (bits-per-second).  This value can be compared with
                the value `si' on interface level (used bandwidth per
                interface).
                This information will only be shown when the kernel module
                `netatop' is loaded.

       BANDWO   Total bandwidth for sent TCP and UDP packets consumed by this
                process (bits-per-second).  This value can be compared with the
                value `so' on interface level (used bandwidth per interface).
                This information will only be shown when the kernel module
                `netatop' is loaded.

       CMD      The name of the process.  This name can be surrounded by
                "less/greater than" signs (`<name>') which means that the
                process has finished during the last interval.
                Behind the abbreviation `CMD' in the header line, the current
                page number and the total number of pages of the process/thread
                list are shown.

       COMMAND-LINE
                The full command line of the process (including arguments). If
                the length of the command line exceeds the length of the screen
                line, the arrow keys -> and <- can be used for horizontal
                scroll.
                Behind the verb `COMMAND-LINE' in the header line, the current
                page number and the total number of pages of the process/thread
                list are shown.

       CPU      The occupation percentage of this process related to the
                available capacity for this resource on system level.

       CPUNR    The identification of the CPU the (main) thread is running on or
                has recently been running on.

       DSK      The occupation percentage of this process related to the total
                load that is produced by all processes (i.e. total disk accesses
                by all processes during the last interval).
                This information is shown when per process "storage accounting"
                is active in the kernel.

       EGID     Effective group-id under which this process executes.

       ENDATE   Date that the process has been finished. If the process is still
                running, this field shows `active'.

       ENTIME   Time that the process has been finished. If the process is still
                running, this field shows `active'.

       EUID     Effective user-id under which this process executes.

       EXC      The exit code of a terminated process (second position of column
                `ST' is E) or the fatal signal number (second position of column
                `ST' is S or C).

       FSGID    Filesystem group-id under which this process executes.

       FSUID    Filesystem user-id under which this process executes.

       MAJFLT   The number of page faults issued by this process that have been
                solved by creating/loading the requested memory page.

       MEM      The occupation percentage of this process related to the
                available capacity for this resource on system level.

       MINFLT   The number of page faults issued by this process that have been
                solved by reclaiming the requested memory page from the free
                list of pages.

       NET      The occupation percentage of this process related to the total
                load that is produced by all processes (i.e. consumed network
                bandwidth of all processes during the last interval).
                This information will only be shown when kernel module `netatop'
                is loaded.

       NICE     The more or less static priority that can be given to a proces
                on a scale from -20 (high priority) to +19 (low priority).

       NPROCS   The number of active and terminated processes accumulated for
                this user or program.

       PID      Process-id.  If a process has been started and finished during
                the last interval, a `?' is shown because the process-id is not
                part of the standard process accounting record.

       POLI     The policies 'norm' (normal, which is SCHED_OTHER), 'btch'
                (batch) and 'idle' refer to timesharing processes.  The policies
                'fifo' (SCHED_FIFO) and 'rr' (round robin, which is SCHED_RR)
                refer to realtime processes.

       PPID     Parent process-id.  If a process has been started and finished
                during the last interval, value 0 is shown because the parent
                process-id is not part of the standard process accounting
                record.

       PRI      The process' priority ranges from 0 (highest priority) to 139
                (lowest priority). Priority 0 to 99 are used for realtime
                processes (fixed priority independent of their behavior) and
                priority 100 to 139 for timesharing processes (variable priority
                depending on their recent CPU consumption and the nice value).

       RDDSK    When the kernel maintains standard io statistics (>= 2.6.20):
                The read data transfer issued physically on disk (so reading
                from the disk cache is not accounted for).

       RGID     The real group-id under which the process executes.

       RGROW    The amount of resident memory that the process has grown during
                the last interval. A resident growth can be caused by touching
                memory pages which were not physically created/loaded before
                (load-on-demand).  Note that a resident growth can also be
                negative e.g. when part of the process is paged out due to lack
                of memory or when the process frees dynamically allocated
                memory.  For a process which started during the last interval,
                the resident growth reflects the total resident size of the
                process at that moment.
                If a process has finished during the last interval, no value is
                shown since resident memory occupation is not part of the
                standard process accounting record.

       RNET     The number of TCP- and UDP packets received by this process.
                This information will only be shown when kernel module `netatop'
                is installed.
                If a process has finished during the last interval, no value is
                shown since network counters are not part of the standard
                process accounting record.

       RSIZE    The total resident memory usage consumed by this process (or
                user).
                If a process has finished during the last interval, no value is
                shown since resident memory occupation is not part of the
                standard process accounting record.

       RTPR     Realtime priority according the POSIX standard.  Value can be 0
                for a timesharing process (policy 'norm', 'btch' or 'idle') or
                ranges from 1 (lowest) till 99 (highest) for a realtime process
                (policy 'rr' or 'fifo').

       RUID     The real user-id under which the process executes.

       S        The current state of the (main) thread: `R' for running
                (currently processing or in the runqueue), `S' for sleeping
                interruptible (wait for an event to occur), `D' for sleeping
                non-interruptible, `Z' for zombie (waiting to be synchronized
                with its parent process), `T' for stopped (suspended or traced),
                `W' for swapping, and `E' (exit) for processes which have
                finished during the last interval.

       SGID     The saved group-id of the process.

       SNET     The number of TCP and UDP packets transmitted by this process.
                This information will only be shown when the kernel module
                `netatop' is loaded.

       ST       The status of a process.
                The first position indicates if the process has been started
                during the last interval (the value N means 'new process').

                The second position indicates if the process has been finished
                during the last interval.
                The value E means 'exit' on the process' own initiative; the
                exit code is displayed in the column `EXC'.
                The value S means that the process has been terminated
                unvoluntarily by a signal; the signal number is displayed in the
                in the column `EXC'.
                The value C means that the process has been terminated
                unvoluntarily by a signal, producing a core dump in its current
                directory; the signal number is displayed in the column `EXC'.

       STDATE   The start date of the process.

       STTIME   The start time of the process.

       SUID     The saved user-id of the process.

       SWAPSZ   The swap space consumed by this process (or user).

       SYSCPU   CPU time consumption of this process in system mode (kernel
                mode), usually due to system call handling.

       TCPRASZ  The average size of a received TCP buffer in bytes.  This
                information will only be shown when the kernel module `netatop'
                is loaded.

       TCPRCV   The number of TCP packets received for this process.  This
                information will only be shown when the kernel module `netatop'
                is loaded.

       TCPSASZ  The average size of a transmitted TCP buffer in bytes.  This
                information will only be shown when the kernel module `netatop'
                is loaded.

       TCPSND   The number of TCP packets transmitted for this process.  This
                information will only be shown when the kernel module `netatop'
                is loaded.

       THR      Total number of threads within this process.  All related
                threads are contained in a thread group, represented by atop as
                one line or as a separate line when the 'y' key (or -y flag) is
                active.

                On Linux 2.4 systems it is hardly possible to determine which
                threads (i.e. processes) are related to the same thread group.
                Every thread is represented by atop as a separate line.

       TID      Thread-id.  All threads within a process run with the same PID
                but with a different TID. This value is shown for individual
                threads in multi-threaded processes (when using the key 'y').

       TRUN     Number of threads within this process that are in the state
                'running' (R).

       TSLPI    Number of threads within this process that are in the state
                'interruptible sleeping' (S).

       TSLPU    Number of threads within this process that are in the state
                'uninterruptible sleeping' (D).

       UDPRASZ  The average size of a received UDP packet in bytes.  This
                information will only be shown when the kernel module `netatop'
                is loaded.

       UDPRCV   The number of UDP packets received by this process.  This
                information will only be shown when the kernel module `netatop'
                is loaded.

       UDPSASZ  The average size of a transmitted UDP packets in bytes.  This
                information will only be shown when the kernel module `netatop'
                is loaded.

       UDPSND   The number of UDP packets transmitted by this process.  This
                information will only be shown when the kernel module `netatop'
                is loaded.

       USRCPU   CPU time consumption of this process in user mode, due to
                processing the own program text.

       VDATA    The virtual memory size of the private data used by this process
                (including heap and shared library data).

       VGROW    The amount of virtual memory that the process has grown during
                the last interval. A virtual growth can be caused by e.g.
                issueing a malloc() or attaching a shared memory segment. Note
                that a virtual growth can also be negative by e.g. issueing a
                free() or detaching a shared memory segment.  For a process
                which started during the last interval, the virtual growth
                reflects the total virtual size of the process at that moment.
                If a process has finished during the last interval, no value is
                shown since virtual memory occupation is not part of the
                standard process accounting record.

       VSIZE    The total virtual memory usage consumed by this process (or
                user).
                If a process has finished during the last interval, no value is
                shown since virtual memory occupation is not part of the
                standard process accounting record.

       VSLIBS   The virtual memory size of the (shared) text of all shared
                libraries used by this process.

       VSTACK   The virtual memory size of the (private) stack used by this
                process

       VSTEXT   The virtual memory size of the (shared) text of the executable
                program.

       WRDSK    When the kernel maintains standard io statistics (>= 2.6.20):
                The write data transfer issued physically on disk (so writing to
                the disk cache is not accounted for).  This counter is
                maintained for the application process that writes its data to
                the cache (assuming that this data is physically transferred to
                disk later on). Notice that disk I/O needed for swapping is not
                taken into account.

       WCANCL   When the kernel maintains standard io statistics (>= 2.6.20):
                The write data transfer previously accounted for this process or
                another process that has been cancelled.  Suppose that a process
                writes new data to a file and that data is removed again before
                the cache buffers have been flushed to disk.  Then the original
                process shows the written data as WRDSK, while the process that
                removes/truncates the file shows the unflushed removed data as
                WCANCL.

PARSEABLE OUTPUT
       With the flag -P followed by a list of one or more labels (comma-
       separated), parseable output is produced for each sample.  The labels
       that can be specified for system-level statistics correspond to the
       labels (first verb of each line) that can be found in the interactive
       output: "CPU", "cpu" "CPL" "MEM", "SWP", "PAG", "LVM", "MDD", "DSK" and
       "NET".
       For process-level statistics special labels are introduced: "PRG"
       (general), "PRC" (cpu), "PRM" (memory), "PRD" (disk, only if "storage
       accounting" is active) and "PRN" (network, only if the kernel module
       'netatop' has been installed).
       With the label "ALL", all system- and process-level statistics are shown.

       For every interval all requested lines are shown whereafter atop shows a
       line just containing the label "SEP" as a separator before the lines for
       the next sample are generated.
       When a sample contains the values since boot, atop shows a line just
       containing the label "RESET" before the lines for this sample are
       generated.

       The first part of each output-line consists of the following six fields:
       label (the name of the label), host (the name of this machine), epoch
       (the time of this interval as number of seconds since 1-1-1970), date
       (date of this interval in format YYYY/MM/DD), time (time of this interval
       in format HH:MM:SS), and interval (number of seconds elapsed for this
       interval).

       The subsequent fields of each output-line depend on the label:

       CPU      Subsequent fields: total number of clock-ticks per second for
                this machine, number of processors, consumption for all CPUs in
                system mode (clock-ticks), consumption for all CPUs in user mode
                (clock-ticks), consumption for all CPUs in user mode for niced
                processes (clock-ticks), consumption for all CPUs in idle mode
                (clock-ticks), consumption for all CPUs in wait mode (clock-
                ticks), consumption for all CPUs in irq mode (clock-ticks),
                consumption for all CPUs in softirq mode (clock-ticks),
                consumption for all CPUs in steal mode (clock-ticks),
                consumption for all CPUs in guest mode (clock-ticks), frequency
                of all CPUs and frequency percentage of all CPUs.

       cpu      Subsequent fields: total number of clock-ticks per second for
                this machine, processor-number, consumption for this CPU in
                system mode (clock-ticks), consumption for this CPU in user mode
                (clock-ticks), consumption for this CPU in user mode for niced
                processes (clock-ticks), consumption for this CPU in idle mode
                (clock-ticks), consumption for this CPU in wait mode (clock-
                ticks), consumption for this CPU in irq mode (clock-ticks),
                consumption for this CPU in softirq mode (clock-ticks),
                consumption for this CPU in steal mode (clock-ticks),
                consumption for this CPU in guest mode (clock-ticks), frequency
                of this CPU and frequency percentage of this CPU.

       CPL      Subsequent fields: number of processors, load average for last
                minute, load average for last five minutes, load average for
                last fifteen minutes, number of context-switches, and number of
                device interrupts.

       MEM      Subsequent fields: page size for this machine (in bytes), size
                of physical memory (pages), size of free memory (pages), size of
                page cache (pages), size of buffer cache (pages), size of slab
                (pages), dirty pages in cache (pages), and reclaimable part of
                slab (pages).

       SWP      Subsequent fields: page size for this machine (in bytes), size
                of swap (pages), size of free swap (pages), 0 (future use), size
                of committed space (pages), and limit for committed space
                (pages).

       PAG      Subsequent fields: page size for this machine (in bytes), number
                of page scans, number of allocstalls, 0 (future use), number of
                swapins, and number of swapouts.

       LVM/MDD/DSK
                For every logical volume/multiple device/hard disk one line is
                shown.
                Subsequent fields: name, number of milliseconds spent for I/O,
                number of reads issued, number of sectors transferred for reads,
                number of writes issued, and number of sectors transferred for
                write.

       NET      First one line is produced for the upper layers of the TCP/IP
                stack.
                Subsequent fields: the verb "upper", number of packets received
                by TCP, number of packets transmitted by TCP, number of packets
                received by UDP, number of packets transmitted by UDP, number of
                packets received by IP, number of packets transmitted by IP,
                number of packets delivered to higher layers by IP, and number
                of packets forwarded by IP.

                Next one line is shown for every interface.
                Subsequent fields: name of the interface, number of packets
                received by the interface, number of bytes received by the
                interface, number of packets transmitted by the interface,
                number of bytes transmitted by the interface, interface speed,
                and duplex mode (0=half, 1=full).

       PRG      For every process one line is shown.
                Subsequent fields: PID (unique ID of task), name (between
                brackets), state, real uid, real gid, TGID (group number of
                related tasks/threads), total number of threads, exit code,
                start time (epoch), full command line (between brackets), PPID,
                number of threads in state 'running' (R), number of threads in
                state 'interruptible sleeping' (S), number of threads in state
                'uninterruptible sleeping' (D), effective uid, effective gid,
                saved uid, saved gid, filesystem uid, filesystem gid, elapsed
                time (hertz) and is_process (y/n).

       PRC      For every process one line is shown.
                Subsequent fields: PID, name (between brackets), state, total
                number of clock-ticks per second for this machine, CPU-
                consumption in user mode (clockticks), CPU-consumption in system
                mode (clockticks), nice value, priority, realtime priority,
                scheduling policy, current CPU, sleep average, TGID (group
                number of related tasks/threads) and is_process (y/n).

       PRM      For every process one line is shown.
                Subsequent fields: PID, name (between brackets), state, page
                size for this machine (in bytes), virtual memory size (Kbytes),
                resident memory size (Kbytes), shared text memory size (Kbytes),
                virtual memory growth (Kbytes), resident memory growth (Kbytes),
                number of minor page faults, number of major page faults,
                virtual library exec size (Kbytes), virtual data size (Kbytes),
                virtual stack size (Kbytes), swap space used (Kbytes), TGID
                (group number of related tasks/threads) and is_process (y/n).

       PRD      For every process one line is shown.
                Subsequent fields: PID, name (between brackets), state,
                obsoleted kernel patch installed ('n'), standard io statistics
                used ('y' or 'n'), number of reads on disk, cumulative number of
                sectors read, number of writes on disk, cumulative number of
                sectors written, cancelled number of written sectors, TGID
                (group number of related tasks/threads) and is_process (y/n).
                If the standard I/O statistics (>= 2.6.20) are not used, the
                disk I/O counters per process are not relevant.  The counters
                'number of reads on disk' and 'number of writes on disk' are
                obsoleted anyhow.

       PRN      For every process one line is shown.
                Subsequent fields: PID, name (between brackets), state, kernel
                module 'netatop' loaded ('y' or 'n'), number of TCP-packets
                transmitted, cumulative size of TCP-packets transmitted, number
                of TCP-packets received, cumulative size of TCP-packets
                received, number of UDP-packets transmitted, cumulative size of
                UDP-packets transmitted, number of UDP-packets received,
                cumulative size of UDP-packets transmitted, number of raw
                packets transmitted (obsolete, always 0), number of raw packets
                received (obsolete, always 0), TGID (group number of related
                tasks/threads) and is_process (y/n).
                If the kernel module is not active, the network I/O counters per
                process are not relevant.

EXAMPLES
       To monitor the current system load interactively with an interval of 5
       seconds:

         atop 5

       To monitor the system load and write it to a file (in plain ASCII) with
       an interval of one minute during half an hour with active processes
       sorted on memory consumption:

         atop -M 60 30 > /log/atop.mem

       Store information about the system- and process activity in binary
       compressed form to a file with an interval of ten minutes during an hour:

         atop -w /tmp/atop.raw 600 6

       View the contents of this file interactively:

         atop -r /tmp/atop.raw

       View the processor- and disk-utilization of this file in parseable
       format:

         atop -PCPU,DSK -r /tmp/atop.raw

       View the contents of today's standard logfile interactively:

         atop -r

       View the contents of the standard logfile of the day before yesterday
       interactively:

         atop -r yy

       View the contents of the standard logfile of 2012, June 7 from 02:00 PM
       onwards interactively:

         atop -r 20120607 -b 14:00

FILES
       /tmp/atop.d/atop.acct
            File in which the kernel writes the accounting records if the
            standard accounting to the file /var/log/pacct or /var/account/pacct
            is not used.

       /etc/atoprc
            Configuration file containing system-wide default values.  See
            related man-page.

       ~/.atoprc
            Configuration file containing personal default values.  See related
            man-page.

       /var/log/atop/atop_YYYYMMDD
            Raw file, where YYYYMMDD are digits representing the current date.
            This name is used by the script atop.daily as default name for the
            output file, and by atop as default name for the input file when
            using the -r flag.
            All binary system- and process-level data in this file has been
            stored in compressed format.

       /var/run/netatop.log
            File that contains the netpertask structs containing the network
            counters of exited processes. These structs are written by the
            netatopd daemon and read by atop after reading the standard process
            accounting records.

SEE ALSO
       atopsar(1), atoprc(5), netatop(4), netatopd(8), logrotate(8)
       http://www.atoptool.nl

AUTHOR
       Gerlof Langeveld (gerlof.langeveld@atoptool.nl)
       JC van Winkel



Linux                             October 2012                           ATOP(1)