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.
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33              How the sa2(8) script applies HISTORY value
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35              The sa2 script uses the "find" command with the "-mtime"  option
36              to  figure out which files are to be removed. The "find" command
37              interprets this value as "N 24 hour periods", ignoring any frac‐
38              tional  part.  This means that the last modified time of a given
39              sa[r]DD data or report file, using a HISTORY of 1, has  to  have
40              been  modified  at least two days ago before it will be removed.
41              And for a HISTORY of 28 that would mean 29 days ago.
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43              To figure out how a HISTORY of 28 is  applied  in  practice,  we
44              need to consider that the sa2 script that issues the "find" com‐
45              mand to remove the old files typically  runs  just  before  mid-
46              night  on  a  given system, and since the first record from sadc
47              can also be written to the previous  day's  data  file  (thereby
48              moving  its  modification  time  up  a bit), the sa2 script will
49              leave 30 files untouched. So for a setting of 28,  and  counting
50              the  data file of the current day, there will always be 31 files
51              (or 30 files, depending on the number of days in a month) in the
52              /var/log/sa directory during the majority of a given day.  E.g.:
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54              April 30th: 31 files (Apr 30th-1st, Mar 31th)
55              May 1st: 30 files (May 1st, Apr 30th-2nd)
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57              Yet  we  can note the following exceptions (as inspected at Noon
58              of the given day):
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60              February 28th: 31 files (Feb 28th-1st, Jan 31st, 30th & 29th)
61              March 1st: 30 files (Mar 1st, Feb 28th-2nd, Jan 31st & 30th)
62              March 2nd: 29 files (Mar 1st & 2nd, Feb 28th-3rd, Jan. 31st)
63              March 3rd: 28 files (Mar 1st-3rd, Feb 28th-4th)
64              March 4th - March 28th: 28 files
65              March 29th: 29 files
66              March 30th: 30 files
67              March 31st: 31 files
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69              (Determining the number of files in March on a leap year is left
70              as an exercise for the reader).
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73       SADC_OPTIONS
74              Options  that  should  be passed to sadc(8).  With these options
75              (see sadc(8) manual page), you can select some  additional  data
76              which  are going to be saved in daily data files.  These options
77              are used only when a new data file  is  created.  They  will  be
78              ignored with an already existing one.
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81       ZIP    Program used to compress data and report files.
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FILES

85       /etc/sysconfig/sysstat
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AUTHOR

89       Sebastien Godard (sysstat <at> orange.fr)
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SEE ALSO

92       sadc(8), sa1(8), sa2(8)
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94       http://pagesperso-orange.fr/sebastien.godard/
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98Linux                              JUNE 2014                        SYSSTAT(5)
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