sysstat(5)

1SYSSTAT(5)                    Linux User's Manual                   SYSSTAT(5)
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NAME

6       sysstat - sysstat configuration file.
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DESCRIPTION

9       This file is read by sa1(8) and sa2(8) shell scripts from the sysstat's
10       set of tools.  It consists of a sequence of shell variable  assignments
11       used  to  configure  sysstat logging.  The variables and their meanings
12       are:
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14       COMPRESSAFTER
15              Number of days after which daily  data  files  are  to  be  com‐
16              pressed.  The compression program is given in the ZIP variable.
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19       HISTORY
20              The  number  of  days during which a daily data file or a report
21              should be kept. Data files or reports older than this number  of
22              days will be removed by the sa2(8) shell script.  Data files and
23              reports are normally saved in the /var/log/sa  directory,  under
24              the name saDD (for data files) or sarDD (for reports), where the
25              DD parameter indicates the current day.
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27              The number of files actually kept in the  /var/log/sa  directory
28              may be slightly higher than the HISTORY value due to the way the
29              sa2 script figures out which files are to be removed (see  below
30              "How the sa2(8) script applies HISTORY value"). Using a value of
31              28 keeps a whole month's worth of data. If you set HISTORY to  a
32              value  greater  than  28  then  you should consider using sadc's
33              option -D to prevent older data  files  from  being  overwritten
34              (see  sadc(8)  manual  page). In this latter case data files are
35              named saYYYYMMDD and reports sarYYYYMMDD, where YYYY stands  for
36              the  current  year, MM for the current month and DD for the cur‐
37              rent day.
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39              How the sa2(8) script applies HISTORY value
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41              The sa2 script uses the "find" command with the "-mtime"  option
42              to  figure out which files are to be removed. The "find" command
43              interprets this value as "N 24 hour periods", ignoring any frac‐
44              tional  part.  This means that the last modified time of a given
45              sa[r]DD data or report file, using a HISTORY of 1, has  to  have
46              been  modified  at least two days ago before it will be removed.
47              And for a HISTORY of 28 that would mean 29 days ago.
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49              To figure out how a HISTORY of 28 is  applied  in  practice,  we
50              need to consider that the sa2 script that issues the "find" com‐
51              mand to remove the old files typically  runs  just  before  mid-
52              night  on  a  given system, and since the first record from sadc
53              can also be written to the previous  day's  data  file  (thereby
54              moving  its  modification  time  up  a bit), the sa2 script will
55              leave 30 files untouched. So for a setting of 28,  and  counting
56              the  data file of the current day, there will always be 31 files
57              (or 30 files, depending on the number of days in a month) in the
58              /var/log/sa directory during the majority of a given day.  E.g.:
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60              April 30th: 31 files (Apr 30th-1st, Mar 31th)
61              May 1st: 30 files (May 1st, Apr 30th-2nd)
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63              Yet  we  can note the following exceptions (as inspected at Noon
64              of the given day):
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66              February 28th: 31 files (Feb 28th-1st, Jan 31st, 30th & 29th)
67              March 1st: 30 files (Mar 1st, Feb 28th-2nd, Jan 31st & 30th)
68              March 2nd: 29 files (Mar 1st & 2nd, Feb 28th-3rd, Jan. 31st)
69              March 3rd: 28 files (Mar 1st-3rd, Feb 28th-4th)
70              March 4th - March 28th: 28 files
71              March 29th: 29 files
72              March 30th: 30 files
73              March 31st: 31 files
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75              (Determining the number of files in March on a leap year is left
76              as an exercise for the reader).
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78              Things  are  simpler  if  you use the sa[r]YYYYMMDD name format.
79              Apply the same logic as above in this case  and  you  will  find
80              that  there  are  always  HISTORY  +  3 files in the /var/log/sa
81              directory during the majority of a given day.
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84       REPORTS
85              Set this variable to false to prevent the sa2 script from gener‐
86              ating reports (the sarDD files).
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89       SA_DIR Directory  where  the  standard  system  activity daily data and
90              report files are saved. Its default value is /var/log/sa.
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93       SADC_OPTIONS
94              Options that should be passed to sadc(8).   With  these  options
95              (see  sadc(8)  manual page), you can select some additional data
96              which are going to be saved in daily data files.  These  options
97              are  used  only  when  a  new data file is created. They will be
98              ignored with an already existing one.
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101       YESTERDAY
102              By default sa2 script generates yesterday's summary,  since  the
103              cron  job  usually runs right after midnight. If you want sa2 to
104              generate the summary of the same day (for example when cron  job
105              runs at 23:53) set this variable to no.
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108       ZIP    Program used to compress data and report files.
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FILES

112       /etc/sysconfig/sysstat
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AUTHOR

116       Sebastien Godard (sysstat <at> orange.fr)
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NAME

DESCRIPTION

FILES

AUTHOR

SEE ALSO