sar  -  Collect,  report, or save system activity informa­
       tion.


SYNOPSIS

       sar [ -A ] [ -b ] [ -B ] [ -c ] [ -d ] [ -h ] [ -i  inter­
       val  ]  [ -q ] [ -r ] [ -R ] [ -t ] [ -u ] [ -v ] [ -V ] [
       -w ] [ -W ] [ -y ] [ -n { DEV | EDEV | SOCK | FULL }  ]  [
       -x  { pid | SELF | SUM | ALL } ] [ -X { pid | SELF | ALL }
       ] [ -I { irq | SUM | PROC | ALL | XALL } ] [ -U  {  cpu  |
       ALL  }  ]  [  -o  [  filename ] | -f [ filename ] ] [ -s [
       hh:mm:ss ] ] [ -e [ hh:mm:ss ] ] [ interval [ count ] ]


DESCRIPTION

       The sar command writes to standard output the contents  of
       selected  cumulative  activity  counters  in the operating
       system. The accounting system, based on the values in  the
       count  and  interval  parameters,  writes  information the
       specified number of times spaced at the  specified  inter­
       vals  in  seconds.   If  the  interval parameter is set to
       zero, the sar command displays the average statistics  for
       the  time  since the system was started. The default value
       for the count parameter is 1. If its value is set to zero,
       then  reports  are  generated continuously.  The collected
       data can also be saved in the file  specified  by  the  -o
       filename  flag,  in  addition  to being displayed onto the
       screen. If filename is omitted, sar uses the standard sys­
       tem  activity  daily data file, the /var/log/sa/sadd file,
       where the dd parameter indicates the current day.

       The sar command extracts and  writes  to  standard  output
       records  previously  saved  in  a  file.  This file can be
       either the one specified by the -f flag  or,  by  default,
       the standard system activity daily data file.

       You  can  select information about specific system activi­
       ties using flags. Not specifying any  flags  selects  only
       CPU  activity.   Specifying  the  -A flag is equivalent to
       specifying -bBcdqrRuvwWy -I SUM -I PROC -n FULL -U ALL.

       The default version of the sar  command  (CPU  utilization
       report) might be one of the first facilities the user runs
       to begin system activity investigation, because  it  moni­
       tors  major  system  resources. If CPU utilization is near
       100 percent (user + nice + system), the  workload  sampled
       is CPU-bound.

       If  multiple  samples and multiple reports are desired, it
       is convenient to specify an output file for the  sar  com­
       mand.   Run  the  sar command as a background process. The
       syntax for this is:

       sar -o data.file interval count >/dev/null 2>&1 &

       (data.file).   The  data can then be selectively displayed
       with the sar command using the -f option.  Set  the  count
       parameter  to select records at count second intervals. If
       this parameter is not set, all the records  saved  in  the
       file  will be selected.  Collection of data in this manner
       is useful to characterize system usage over  a  period  of
       time and determine peak usage hours.

       Note:     The  sar  command  only reports on local activi­
       ties.


OPTIONS

       -A     This is equivalent to specifying  -bBcdqrRuvwWy  -I
              SUM -I PROC -n FULL -U ALL.

       -b     Report  I/O  and transfer rate statistics. The fol­
              lowing values are displayed:

              tps
                     Total number of transfers  per  second  that
                     were  issued to the physical disk.  A trans­
                     fer is an I/O request to the physical  disk.
                     Multiple  logical  requests  can be combined
                     into a single I/O request to  the  disk.   A
                     transfer is of indeterminate size.

              rtps
                     Total  number  of  read  requests per second
                     issued to the physical disk.

              wtps
                     Total number of write  requests  per  second
                     issued to the physical disk.

              bread/s
                     Total  amount of data read from the drive in
                     blocks per second.  A block is of indetermi­
                     nate size.

              bwrtn/s
                     Total amount of data written to the drive in
                     blocks per second.

       -B     Report paging statistics. The following values  are
              displayed:

              pgpgin/s
                     Total  number  of blocks the system paged in
                     from disk per second.

              pgpgout/s
                     Total number of blocks the system paged  out


              activepg
                     Number of active (recently touched) pages in
                     memory.  Note that a page has a size of 4 KB
                     or  8  KB according to the machine architec­
                     ture.

              inadtypg
                     Number of inactive dirty (modified or poten­
                     tially modified) pages in memory.

              inaclnpg
                     Number  of  inactive  clean  (not  modified)
                     pages in memory.

              inatarpg
                     "Inactive  target"  number  of  pages.  This
                     field  is a 1-minute floating average of the
                     number of pages the system needs to  "steal"
                     every  second  in  order  to  satisfy memory
                     demand.

       -c     Report process creation activity.

              proc/s
                     Total number of processes created  per  sec­
                     ond.

       -d     Report  activity for each block device (kernels 2.4
              and later only). When data is displayed, the device
              specification  dev m-n is generally used ( DEV col­
              umn).  m is the major number of the device, whereas
              n is a distinctive number.

              tps
                     Indicate  the number of transfers per second
                     that were issued to  the  device.   Multiple
                     logical requests can be combined into a sin­
                     gle I/O request to the device. A transfer is
                     of indeterminate size.

              blks/s
                     Number  of blocks transferred from or to the
                     device. A block is of indeterminate size.

       -e hh:mm:ss
              Set the ending time of the report. The default end­
              ing  time  is  18:00:00.  Hours  must  be  given in
              24-hour format.  This option can be used only  when
              data are read from or written to a file (options -f
              or -o ).

              Extract records from filename (created  by  the  -o
              filename  flag).  The default value of the filename
              parameter is  the  current  daily  data  file,  the
              /var/log/sa/sadd  file.  The -f option is exclusive
              of the -o option.

       -h     When  reading data from a file, print its  contents
              in  a  format that can easily be handled by pattern
              processing commands like awk.  The output  consists
              of columns separated by a tab. The columns are: The
              machine hostname, the interval value (or -1 if  not
              applicable),  the  timestamp  (UST time) in seconds
              from the epoch, the device name (or - if not appli­
              cable), the field name and its value.

       -i interval
              Select data records at seconds as close as possible
              to the number specified by the interval  parameter.

       -I irq | SUM | PROC | ALL | XALL
              Report  statistics  for  a given interrupt.  irq is
              the interrupt number.  The  SUM  keyword  indicates
              that  the  total  number of interrupts received per
              second is to be displayed. The  ALL  keyword  indi­
              cates  that statistics from the first 16 interrupts
              are to be reported, whereas the XALL keyword  indi­
              cates  that statistics from all interrupts, includ­
              ing potential APIC interrupt  sources,  are  to  be
              reported.   Last,  if you use the PROC keyword, the
              number of interrupts per second  received  by  each
              processor is displayed.

       -n DEV | EDEV | SOCK | FULL
              Report network statistics.

              With  the  DEV keyword, statistics from the network
              devices are reported.   The  following  values  are
              displayed:

              IFACE
                     Name  of  the  network  interface  for which
                     statistics are reported.

              rxpck/s
                     Total number of packets received per second.

              txpck/s
                     Total number of packets transmitted per sec­
                     ond.

              rxbyt/s
                     Total number of bytes received per second.

                     Total number of bytes transmitted  per  sec­
                     ond.

              rxcmp/s
                     Number  of  compressed  packets received per
                     second (for cslip etc.).

              txcmp/s
                     Number of compressed packets transmitted per
                     second.

              rxmcst/s
                     Number  of  multicast  packets  received per
                     second.

              With  the  EDEV  keyword,  statistics  on  failures
              (errors)  from  the  network  devices are reported.
              The following values are displayed:

              IFACE
                     Name of  the  network  interface  for  which
                     statistics are reported.

              rxerr/s
                     Total  number  of  bad  packets received per
                     second.

              txerr/s
                     Total number of  errors  that  happened  per
                     second while transmitting packets.

              coll/s
                     Number  of collisions that happened per sec­
                     ond while transmitting packets.

              rxdrop/s
                     Number of received packets dropped per  sec­
                     ond  because  of  a  lack  of space in linux
                     buffers.

              txdrop/s
                     Number of transmitted  packets  dropped  per
                     second  because  of a lack of space in linux
                     buffers.

              txcarr/s
                     Number of carrier-errors that  happened  per
                     second while transmitting packets.

              rxfram/s
                     Number  of  frame alignment errors that hap­
                     pened per second on received packets.

                     Number of FIFO overrun errors that  happened
                     per second on received packets.

              txfifo/s
                     Number  of FIFO overrun errors that happened
                     per second on transmitted packets.

              With the SOCK keyword, statistics on sockets in use
              are reported.  The following values are displayed:

              totsck
                     Total number of used sockets.

              tcpsck
                     Number of TCP sockets currently in use.

              udpsck
                     Number of UDP sockets currently in use.

              rawsck
                     Number of RAW sockets currently in use.

              ip-frag
                     Number of IP fragments currently in use.

              The  FULL  keyword  is equivalent to specifying all
              the keywords above and therefore  all  the  network
              activities are reported.

       -o filename
              Save  the readings in the file in binary form. Each
              reading is in a separate record. The default  value
              of the filename parameter is the current daily data
              file, the /var/log/sa/sadd file. The -o  option  is
              exclusive of the -f option.

       -q     Report  queue length and load averages. The follow­
              ing values are displayed:

              runq-sz
                     Run queue length (number of processes  wait­
                     ing for run time).

              plist-sz
                     Number of processes in the process list.

              ldavg-1
                     System load average for the last minute.

              ldavg-5
                     System  load average for the past 5 minutes.

       -r     Report   memory   and   swap   space    utilization


              kbmemfree
                     Amount  of  free  memory  available in kilo­
                     bytes.

              kbmemused
                     Amount of used  memory  in  kilobytes.  This
                     does  not  take  into account memory used by
                     the kernel itself.

              %memused
                     Percentage of used memory.

              kbmemshrd
                     Amount of memory shared  by  the  system  in
                     kilobytes.  Always zero with 2.4 kernels.

              kbbuffers
                     Amount of memory used as buffers by the ker­
                     nel in kilobytes.

              kbcached
                     Amount of memory used to cache data  by  the
                     kernel in kilobytes.

              kbswpfree
                     Amount of free swap space in kilobytes.

              kbswpused
                     Amount of used swap space in kilobytes.

              %swpused
                     Percentage of used swap space.

       -R     Report  memory statistics. The following values are
              displayed:

              frmpg/s
                     Number of memory pages freed by  the  system
                     per  second.   A negative value represents a
                     number of pages  allocated  by  the  system.
                     Note  that a page has a size of 4 KB or 8 KB
                     according to the machine architecture.

              shmpg/s
                     Number of additionnal memory pages shared by
                     the  system  per  second.   A negative value
                     means fewer pages shared by the system.

              bufpg/s
                     Number of additionnal memory pages  used  as
                     buffers  by  the system per second.  A nega­
                     tive value means fewer pages used as buffers


              campg/s
                     Number of additionnal memory pages cached by
                     the system per  second.   A  negative  value
                     means fewer pages in the cache.

       -s hh:mm:ss
              Set  the starting time of the data, causing the sar
              command to extract records time-tagged at, or  fol­
              lowing,  the  time  specified. The default starting
              time is 08:00.  Hours must be given in 24-hour for­
              mat.  This  option  can  be used only when data are
              read from a file (option -f ).

       -t     When reading data from a daily data file,  indicate
              that sar should display the timestamps in the orig­
              inal locale time of the data file creator.  Without
              this  option,  the  sar command displays the times­
              tamps in the user locale time.

       -u     Report CPU utilization. The  following  values  are
              displayed:

              %user
                     Percentage  of CPU utilization that occurred
                     while executing at the user level  (applica­
                     tion).

              %nice
                     Percentage  of CPU utilization that occurred
                     while executing at the user level with  nice
                     priority.

              %system
                     Percentage  of CPU utilization that occurred
                     while executing at the  system  level  (ker­
                     nel).

              %idle
                     Percentage of time that the CPU or CPUs were
                     idle.

       -U cpu | ALL
              Report CPU utilization for a given processor.   cpu
              is  the processor number. The ALL keyword indicates
              that statistics are to be reported for all  proces­
              sors. Note that processor 0 is the first processor.

       -v     Report status  of  inode,  file  and  other  kernel
              tables.  The following values are displayed:

              dentunusd
                     Number   of  unused  cache  entries  in  the


              file-sz
                     Number of used file handles.

              %file-sz
                     Percentage of used file handles with  regard
                     to  the  maximum number of file handles that
                     the Linux kernel can allocate.

              inode-sz
                     Number of used inode handlers.

              super-sz
                     Number of super block handlers allocated  by
                     the kernel.

              %super-sz
                     Percentage of allocated super block handlers
                     with regard to the maximum number  of  super
                     block handlers that Linux can allocate.

              dquot-sz
                     Number of allocated disk quota entries.

              %dquot-sz
                     Percentage  of  allocated disk quota entries
                     with regard to the maximum number of  cached
                     disk quota entries that can be allocated.

              rtsig-sz
                     Number of queued RT signals.

              %rtsig-sz
                     Percentage  of queued RT signals with regard
                     to the maximum number of RT signals that can
                     be queued.

       -V     Print version number and usage then exit.

       -w     Report system switching activity.

              cswch/s
                     Total number of context switches per second.

       -W     Report swapping statistics.  The  following  values
              are displayed:

              pswpin/s
                     Total   number  of  swap  pages  the  system
                     brought in per second.

              pswpout/s
                     Total  number  of  swap  pages  the   system


       -x pid | SELF | SUM | ALL
              Report  statistics for a given process.  pid is the
              process identification  number.  The  SELF  keyword
              indicates  that  statistics  are to be reported for
              the sar process itself,  whereas  the  ALL  keyword
              indicates  that  statistics  are to be reported for
              all the system processes.  When the SUM keyword  is
              used,  the  total  number of minor and major faults
              made by the system is reported. All  these  statis­
              tics  cannot  be  saved  to a file.  So this option
              will be ignored whenever -o option is used.  At the
              present  time,  no  more  than 256 processes can be
              monitored simultaneously.

              When the SUM keyword is  not  used,  the  following
              values are displayed:

              minflt/s
                     Total number of minor faults the process has
                     made  per  second,  those  which  have   not
                     required loading a memory page from disk.

              majflt/s
                     Total number of major faults the process has
                     made per second, those which  have  required
                     loading a memory page from disk.

              %user
                     Percentage  of CPU used by the process while
                     executing at the user level (application).

              %system
                     Percentage of CPU used by the process  while
                     executing at the system level (kernel).

              nswap/s
                     Number  of  pages  from  the process address
                     space the system has swapped out per second.

              CPU
                     Processor  number  to  which  the process is
                     attached.

              When the SUM keyword is used on the  command  line,
              the following values are displayed:

              minflt/s
                     Total  number of minor faults the system has
                     made  per  second,  those  which  have   not
                     required loading a memory page from disk.

              majflt/s

                     made per second, those which  have  required
                     loading a memory page from disk.

              These  last two statistics are consistent only when
              no processes have  terminated.   If  a  process  is
              killed  during the interval, the statistics are not
              available (marked as ????) and the  average  number
              will not be computed.

       -X pid | SELF | ALL
              Report  statistics  for  the child processes of the
              process whose PID is pid .  The SELF keyword  indi­
              cates  that  statistics  are to be reported for the
              child processes of the sar process itself,  whereas
              the ALL keyword indicates that statistics are to be
              reported for all the child  processes  of  all  the
              system  processes.   All these statistics cannot be
              saved to a file.  So this option  will  be  ignored
              whenever  -o  option is used.  At the present time,
              no more than 256 processes can be monitored  simul­
              taneously.  The following values are displayed:

              cminflt/s
                     Total  number of minor faults the child pro­
                     cesses have made  per  second,  those  which
                     have not required loading a memory page from
                     disk.

              cmajflt/s
                     Total number of major faults the child  pro­
                     cesses  have  made  per  second, those which
                     have required loading  a  memory  page  from
                     disk.

              %cuser
                     Percentage  of  CPU  used  by the child pro­
                     cesses while executing  at  the  user  level
                     (application).

              %csystem
                     Percentage  of  CPU  used  by the child pro­
                     cesses while executing at the  system  level
                     (kernel).

              cnswap/s
                     Number  of  pages  from  the  child  process
                     address spaces the system  has  swapped  out
                     per second.

       -y     Report  TTY  device  activity. The following values
              are displayed:

              rcvin/s

                     current  serial  line. Serial line number is
                     given in the TTY column.

              xmtin/s
                     Number of transmit interrupts per second for
                     current serial line.


ENVIRONMENT

       The  sar command takes into account the following environ­
       ment variable:

       S_TIME_FORMAT
              If this variable exists and its value is  ISO  then
              the  current  locale  will be ignored when printing
              the date in the report  header.   The  sar  command
              will use the ISO format (YYYY-MM-DD) instead.


EXAMPLES

       sar -u 2 5
              Report  CPU utilization for each 2 seconds. 5 lines
              are displayed.

       sar -I 14 -o int14.file 2 10
              Report statistics on IRQ 14 for each 2 seconds.  10
              lines  are  displayed.   Data  are stored in a file
              called int14.file.


BUGS

       /proc filesystem must be mounted for the  sar  command  to
       work.

       All  the statistics are not necessarily available, depend­
       ing on  the  kernel  version  used.   In  particular,  TTY
       statistics (option -y) are not available in 2.2.x SMP ker­
       nels (with x <= 15), because of an SMP race that  sar  may
       trigger when reading the /proc/tty/driver/serial file.


FILES

       /var/log/sa/sadd
              Indicate  the daily data file, where the dd parame­
              ter is a number representing the day of the  month.

       /proc contains various files with system statistics.


AUTHOR

       Sebastien Godard <sebastien.godard@wanadoo.fr>


SEE ALSO

       sadc(8),  sa1(8),  sa2(8),  isag(1), mpstat(1), iostat(1),
       vmstat(8)



Man(1) output converted with man2html