Provided by: sysstat_12.5.2-2ubuntu0.2_amd64 bug

NAME

       sysstat - sysstat configuration file.

DESCRIPTION

       This  file is read by sa1(8) and sa2(8) shell scripts from the sysstat's set of tools.  It
       consists of a sequence of shell variable assignments used to  configure  sysstat  logging.
       The variables and their meanings are:

       COMPRESSAFTER
              Number  of days after which daily data files are to be compressed.  The compression
              program is given in the ZIP variable.

       DELAY_RANGE
              Tell sa2 script to wait for a random delay in the indicated range  before  running.
              This  delay is expressed in seconds, and is aimed at preventing a massive I/O burst
              at the same time on VM sharing the same storage area.  A value of 0 means that  sa2
              script will generate its reports files immediately.

       HISTORY
              The  number of days during which a daily data file or a report should be kept. Data
              files or reports older than this number of days will be removed by the sa2(8) shell
              script.   Data  files  and  reports  are  normally  saved  in  the /var/log/sysstat
              directory, under the name saDD (for data files) or sarDD (for reports),  where  the
              DD parameter indicates the current day.

              The number of files actually kept in the /var/log/sysstat directory may be slightly
              higher than the HISTORY value due to the way the sa2 script figures out which files
              are  to be removed (see below "How the sa2(8) script applies HISTORY value"). Using
              a value of 28 keeps a whole month's worth of data. If you set HISTORY  to  a  value
              greater  than  28  then you should consider using sadc's option -D to prevent older
              data files from being overwritten (see sadc(8) manual page). In  this  latter  case
              data  files are named saYYYYMMDD and reports sarYYYYMMDD, where YYYY stands for the
              current year, MM for the current month and DD for the current day.

              How the sa2(8) script applies HISTORY value

              The sa2 script uses the find command with the -mtime option  to  figure  out  which
              files  are  to  be  removed.  The  find command interprets this value as "N 24 hour
              periods", ignoring any fractional part. This means that the last modified time of a
              given  sa[r]DD data or report file, using a HISTORY of 1, has to have been modified
              at least two days ago before it will be removed. And for a HISTORY of 28 that would
              mean 29 days ago.

              To  figure out how a HISTORY of 28 is applied in practice, we need to consider that
              the sa2 script that issues the find command to remove the old files typically  runs
              just  before  mid-night on a given system, and since the first record from sadc can
              also be written to the previous day's data file (thereby  moving  its  modification
              time  up  a bit), the sa2 script will leave 30 files untouched. So for a setting of
              28, and counting the data file of the current day, there will always  be  31  files
              (or  30  files, depending on the number of days in a month) in the /var/log/sysstat
              directory during the majority of a given day.  E.g.:

              April 30th: 31 files (Apr 30th-1st, Mar 31th)
              May 1st: 30 files (May 1st, Apr 30th-2nd)

              Yet we can note the following exceptions (as inspected at Noon of the given day):

              February 28th: 31 files (Feb 28th-1st, Jan 31st, 30th & 29th)
              March 1st: 30 files (Mar 1st, Feb 28th-2nd, Jan 31st & 30th)
              March 2nd: 29 files (Mar 1st & 2nd, Feb 28th-3rd, Jan. 31st)
              March 3rd: 28 files (Mar 1st-3rd, Feb 28th-4th)
              March 4th - March 28th: 28 files
              March 29th: 29 files
              March 30th: 30 files
              March 31st: 31 files

              (Determining the number of files in March on a leap year is left as an exercise for
              the reader).

              Things  are simpler if you use the sa[r]YYYYMMDD name format.  Apply the same logic
              as above in this case and you will find that there are always HISTORY + 3 files  in
              the /var/log/sysstat directory during the majority of a given day.

       REPORTS
              Set  this  variable to false to prevent the sa2 script from generating reports (the
              sarDD files).

       SA_DIR Directory where the standard system activity daily data and report files are saved.
              Its default value is /var/log/sysstat.

       SADC_OPTIONS
              Options  that  should be passed to sadc(8).  With these options (see sadc(8) manual
              page), you can select some additional data which are going to  be  saved  in  daily
              data files.  These options are used only when a new data file is created. They will
              be ignored with an already existing one.

       YESTERDAY
              By default sa2 script generates yesterday's summary, since  the  cron  job  usually
              runs  right after midnight. If you want sa2 to generate the summary of the same day
              (for example when cron job runs at 23:53) set this variable to no.

       ZIP    Program used to compress data and report files.

FILE

       /etc/sysstat/sysstat

AUTHOR

       Sebastien Godard (sysstat <at> orange.fr)

SEE ALSO

       sadc(8), sa1(8), sa2(8)

       https://github.com/sysstat/sysstat
       http://pagesperso-orange.fr/sebastien.godard/