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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 line-
     len] [-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 sys-
     tem.  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 re-
     source occupation on system level (cpu, memory, disks and network	layers),
     followed  by a list of processes which have been active during the last in-
     terval (note that all processes that were unchanged during the last  inter-
     val  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 con-
     nected 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 au-
     tomatically.  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. Specify-
     ing  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 for-
     mat (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 informa-
     tion 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.  There-
     fore  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  ac-
     counting 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 ac-
     counting 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 account-
     ing 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 mes-
     sage  `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 criti-
     cal occupation percentage means that is likely that this load causes a not-
     icable negative performance influence for applications using this resource.
     The critical percentage depends on the type of resource: e.g.  the  perfor-
     mance influence of a disk with a busy percentage of 80% might be more noti-
     cable 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  sepa-
     rate 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 num-
     ber 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  men-
     tioned 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 account-
	  ing", 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 re-
	  ceived 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 in-
	  stalled.

	  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 occu-
	  pation 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  ar-
	  guments.

     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 differ-
	  ent  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 com-
	  mand `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 com-
	  mand `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 sys-
	  tem  resource during this interval.  The one-but-last column shows ei-
	  ther ``ACPU'', ``AMEM'', ``ADSK'' or ``ANET'' (the preceding 'A' indi-
	  cates 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 back-
	  ward).

     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 expres-
	  sion.  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  ex-
	  pression.  From now on, only processes will be shown with a name which
	  matches  the regular expression.  The system statistics are still sys-
	  tem 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  expres-
	  sion.  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/accu-
	  mulating the processes that were active during the last interval  (de-
	  fault) 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  re-
	  sources  (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 dur-
	  ing 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  speci-
	  fied	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 analy-
     sis (e.g. to check the system load and the active processes running yester-
     day 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  fol-
     lowed  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: infi-
     nite) 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_YYYYM-
     MDD  is  opened.  If a filename with the symbolic name y is specified, yes-
     terday'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 argu-
     ment 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/logro-
     tate.d/psaccs_atop takes care that atop is finished just before  the  rota-
     tion   of	 the   process	 accounting   file   and  the  file  /etc/logro-
     tate.d/psaccu_atop takes care that atop is restarted again after the  rota-
     tion.   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 coun-
     ters 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 activ-
     ity. 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 mo-
	  ment 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  pro-
	  cacct`).
	  If the screen-width does not allow all of these counters, only a rele-
	  vant subset is shown.

     CPU  CPU utilization.
	  At  least  one  line is shown for the total occupation of all CPUs to-
	  gether.
	  In case of a multi-processor system, an additional line is  shown  for
	  every  individual  processor (with `cpu' in lower case), sorted on ac-
	  tivity. 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 run-
	  ning 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 show-
	  ing the per-cpu occupation can be limited.

	  For virtual machines the steal-percentage is shown (`steal'), reflect-
	  ing the percentage of cpu time stolen by other virtual  machines  run-
	  ning 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 issue-
	  ing `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 rele-
	  vant 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 ser-
	  viced interrupts (`intr') and the number of available CPUs are shown.

	  If the screen-width does not allow all of these counters, only a rele-
	  vant 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 mem-
	  ory 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 rele-
	  vant 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 maxi-
	  mum  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 ex-
	  ceeds the limit if strict overcommit handling is configured  (vm.over-
	  commit_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  num-
	  ber 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  re-
	  quests 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 rele-
	  vant 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 re-
	  transmitted  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 rele-
	  vant subset is shown.
	  These counters are related to IPv4 and IPv6 combined.

	  For the IP layer, counters are shown concerning the number of IP data-
	  grams  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 (`de-
	  liv'), 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 rele-
	  vant 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 du-
	  plex is determined by comparing the interface speed with the number of
	  bits	transmitted  and received per second; for full duplex the inter-
	  face 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  per-
	  centage.
	  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 mul-
	  ticast 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 rele-
	  vant 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), de-
     pending 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 `ne-
	      tatop' 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  `ne-
	      tatop' 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  pri-
	      ority  100 to 139 for timesharing processes (variable priority de-
	      pending 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  nega-
	      tive  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 mo-
	      ment.
	      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 in-
	      stalled.
	      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  `ne-
	      tatop' is loaded.

     ST       The status of a process.
	      The  first position indicates if the process has been started dur-
	      ing 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 unvoluntar-
	      ily by a signal; the signal number is displayed in the in the col-
	      umn `EXC'.
	      The value C means that the process has been terminated unvoluntar-
	      ily 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 informa-
	      tion  will  only	be  shown  when  the  kernel module `netatop' is
	      loaded.

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

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

     TCPSND   The number of TCP packets transmitted for this process.  This  in-
	      formation  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 'run-
	      ning' (R).

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

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

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

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

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

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

     USRCPU   CPU time consumption of this process in user mode, due to process-
	      ing 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 li-
	      braries 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 (as-
	      suming that this data is physically transferred to disk later on).
	      Notice that disk I/O needed for swapping is  not	taken  into  ac-
	      count.

     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-sepa-
     rated), 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" (gen-
     eral), "PRC" (cpu), "PRM" (memory), "PRD" (disk, only if "storage	account-
     ing" 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 con-
     taining 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),  con-
	      sumption	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), con-
	      sumption 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 re-
	      ceived by UDP, number of packets transmitted  by	UDP,  number  of
	      packets  received by IP, number of packets transmitted by IP, num-
	      ber 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 re-
	      ceived by the interface, number of bytes received  by  the  inter-
	      face,  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 brack-
	      ets), 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 'inter-
	      ruptible	sleeping'  (S), number of threads in state 'uninterrupt-
	      ible 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 num-
	      ber of clock-ticks per second for this machine, CPU-consumption in
	      user  mode  (clockticks),  CPU-consumption  in system mode (clock-
	      ticks), nice value, priority, realtime priority,	scheduling  pol-
	      icy,  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), resi-
	      dent memory size (Kbytes), shared text memory size (Kbytes),  vir-
	      tual memory growth (Kbytes), resident memory growth (Kbytes), num-
	      ber of minor page faults, number of major page faults, virtual li-
	      brary  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 trans-
	      mitted, 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  trans-
	      mitted,  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 sec-
     onds:

       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 com-
     pressed 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  in-
     teractively:

       atop -r yy

     View the contents of the standard logfile of 2012, June 7 from 02:00 PM on-
     wards 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 coun-
	  ters	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)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=atop&sektion=1&manpath=FreeBSD+Ports+15.1.quarterly>

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