{ "mode": "man", "parameter": "sysstat", "section": "5", "url": "https://www.chedong.com/phpMan.php/man/sysstat/5/json", "generated": "2026-05-30T06:05:27Z", "sections": { "NAME": { "content": "sysstat - sysstat configuration file.\n\n", "subsections": [] }, "DESCRIPTION": { "content": "This file is read by sa1(8) and sa2(8) shell scripts from the sysstat's set of tools. It\nconsists of a sequence of shell variable assignments used to configure sysstat logging. The\nvariables and their meanings are:\n\nCOMPRESSAFTER\nNumber of days after which daily data files are to be compressed. The compression\nprogram is given in the ZIP variable.\n\nDELAYRANGE\nTell sa2 script to wait for a random delay in the indicated range before running.\nThis delay is expressed in seconds, and is aimed at preventing a massive I/O burst at\nthe same time on VM sharing the same storage area. A value of 0 means that sa2 script\nwill generate its reports files immediately.\n\nHISTORY\nThe number of days during which a daily data file or a report should be kept. Data\nfiles or reports older than this number of days will be removed by the sa2(8) shell\nscript. Data files and reports are normally saved in the /var/log/sysstat directory,\nunder the name saDD (for data files) or sarDD (for reports), where the DD parameter\nindicates the current day.\n\nThe number of files actually kept in the /var/log/sysstat directory may be slightly\nhigher than the HISTORY value due to the way the sa2 script figures out which files\nare to be removed (see below \"How the sa2(8) script applies HISTORY value\"). Using a\nvalue of 28 keeps a whole month's worth of data. If you set HISTORY to a value greater\nthan 28 then you should consider using sadc's option -D to prevent older data files\nfrom being overwritten (see sadc(8) manual page). In this latter case data files are\nnamed saYYYYMMDD and reports sarYYYYMMDD, where YYYY stands for the current year, MM\nfor the current month and DD for the current day.\n\nHow the sa2(8) script applies HISTORY value\n\nThe sa2 script uses the find command with the -mtime option to figure out which files\nare to be removed. The find command interprets this value as \"N 24 hour periods\", ig‐\nnoring any fractional part. This means that the last modified time of a given sa[r]DD\ndata or report file, using a HISTORY of 1, has to have been modified at least two days\nago before it will be removed. And for a HISTORY of 28 that would mean 29 days ago.\n\nTo figure out how a HISTORY of 28 is applied in practice, we need to consider that the\nsa2 script that issues the find command to remove the old files typically runs just\nbefore mid-night on a given system, and since the first record from sadc can also be\nwritten to the previous day's data file (thereby moving its modification time up a\nbit), the sa2 script will leave 30 files untouched. So for a setting of 28, and count‐\ning the data file of the current day, there will always be 31 files (or 30 files, de‐\npending on the number of days in a month) in the /var/log/sysstat directory during the\nmajority of a given day. E.g.:\n\nApril 30th: 31 files (Apr 30th-1st, Mar 31th)\nMay 1st: 30 files (May 1st, Apr 30th-2nd)\n\nYet we can note the following exceptions (as inspected at Noon of the given day):\n\nFebruary 28th: 31 files (Feb 28th-1st, Jan 31st, 30th & 29th)\nMarch 1st: 30 files (Mar 1st, Feb 28th-2nd, Jan 31st & 30th)\nMarch 2nd: 29 files (Mar 1st & 2nd, Feb 28th-3rd, Jan. 31st)\nMarch 3rd: 28 files (Mar 1st-3rd, Feb 28th-4th)\nMarch 4th - March 28th: 28 files\nMarch 29th: 29 files\nMarch 30th: 30 files\nMarch 31st: 31 files\n\n(Determining the number of files in March on a leap year is left as an exercise for\nthe reader).\n\nThings are simpler if you use the sa[r]YYYYMMDD name format. Apply the same logic as\nabove in this case and you will find that there are always HISTORY + 3 files in the\n/var/log/sysstat directory during the majority of a given day.\n\nREPORTS\nSet this variable to false to prevent the sa2 script from generating reports (the\nsarDD files).\n\nSADIR Directory where the standard system activity daily data and report files are saved.\nIts default value is /var/log/sysstat.\n\nSADCOPTIONS\nOptions that should be passed to sadc(8). With these options (see sadc(8) manual\npage), you can select some additional data which are going to be saved in daily data\nfiles. These options are used only when a new data file is created. They will be ig‐\nnored with an already existing one.\n\nYESTERDAY\nBy default sa2 script generates yesterday's summary, since the cron job usually runs\nright after midnight. If you want sa2 to generate the summary of the same day (for ex‐\nample when cron job runs at 23:53) set this variable to no.\n\nZIP Program used to compress data and report files.\n\n", "subsections": [] }, "FILE": { "content": "/etc/sysstat/sysstat\n\n", "subsections": [] }, "AUTHOR": { "content": "Sebastien Godard (sysstat orange.fr)\n\n", "subsections": [] }, "SEE ALSO": { "content": "sadc(8), sa1(8), sa2(8)\n\nhttps://github.com/sysstat/sysstat\nhttp://pagesperso-orange.fr/sebastien.godard/\n\n\n\nLinux JULY 2020 SYSSTAT(5)", "subsections": [] } }, "summary": "sysstat - sysstat configuration file.", "flags": [], "examples": [], "see_also": [ { "name": "sadc", "section": "8", "url": "https://www.chedong.com/phpMan.php/man/sadc/8/json" }, { "name": "sa1", "section": "8", "url": "https://www.chedong.com/phpMan.php/man/sa1/8/json" }, { "name": "sa2", "section": "8", "url": "https://www.chedong.com/phpMan.php/man/sa2/8/json" } ] }