# sysstat(5) - man - phpMan [SYSSTAT(5)](https://www.chedong.com/phpMan.php/man/SYSSTAT/5/markdown) Linux User's Manual [SYSSTAT(5)](https://www.chedong.com/phpMan.php/man/SYSSTAT/5/markdown) ## NAME sysstat - sysstat configuration file. ## DESCRIPTION This file is read by [**sa1**(8)](https://www.chedong.com/phpMan.php/man/sa1/8/markdown) and [**sa2**(8)](https://www.chedong.com/phpMan.php/man/sa2/8/markdown) 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)](https://www.chedong.com/phpMan.php/man/sa2/8/markdown) 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)](https://www.chedong.com/phpMan.php/man/sa2/8/markdown) 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)](https://www.chedong.com/phpMan.php/man/sadc/8/markdown) 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)](https://www.chedong.com/phpMan.php/man/sa2/8/markdown) 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", ig‐ noring 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 count‐ ing the data file of the current day, there will always be 31 files (or 30 files, de‐ pending 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)](https://www.chedong.com/phpMan.php/man/sadc/8/markdown). With these options (see [**sadc**(8)](https://www.chedong.com/phpMan.php/man/sadc/8/markdown) 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 ig‐ nored 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 ex‐ ample 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 orange.fr) ## SEE ALSO [**sadc**(8)](https://www.chedong.com/phpMan.php/man/sadc/8/markdown), [**sa1**(8)](https://www.chedong.com/phpMan.php/man/sa1/8/markdown), [**sa2**(8)](https://www.chedong.com/phpMan.php/man/sa2/8/markdown) _ _ Linux JULY 2020 [SYSSTAT(5)](https://www.chedong.com/phpMan.php/man/SYSSTAT/5/markdown)