sa is a command-line utility that is part of the acct package in Linux. It is used to summarize and report on system accounting information, including information on user commands, CPU time spent processing, and I/O rates.
The acct package is a set of tools that enable system administrators to monitor and analyze system resource usage. It provides a way to track system performance over time, and can be used to identify potential performance bottlenecks or to generate reports on user activity.
The sa command is used to generate reports from the system accounting files, which are generated by the acct package. These files contain information on user commands, CPU time spent processing, I/O rates, and other system resource usage data.
Here are some of the features and capabilities of as:
- Command summaries: sa can be used to generate reports that summarize the commands executed by users, including the number of times each command was executed, the amount of CPU time spent processing each command, and the I/O rates associated with each command.
- User summaries: sa can also be used to generate reports that summarize the activity of individual users. These reports provide information on the number of commands executed by each user, the amount of CPU time spent by each user, and the I/O rates associated with each user.
- Time period summaries: sa can generate reports that summarize system resource usage over a specific time period. This is useful for identifying trends in system performance and resource usage over time.
sa Command Examples
1. To summarize accounting information:
# sa
2. To list all and not to sort:
# sa -a # sa --list-all-names
3. To Sort the output by the sum of user and system time divided by the number of calls:
# sa -b # sa --sort-sys-user-div-calls
4. To Print percentages of total time for the commandâs user, system, and real time values:
# sa -c # sa --percentages
5. To assume that all answers to interactive queries as affirmative:
# sa -f # sa --not-interactive
5. To don’t read the information in the systemâs default savacct file:
# sa -I # sa --dont-read-summary-file
6. To print seconds per call:
# sa -j # sa --print-seconds
7. To Sort the output by cpu time average memory usage:
# sa -k # sa --sort-cpu-avmem
8. To Print and sort the output by the cpu-storage integral:
# sa -K # sa --sort-ksec
9. To Print separate columns for system and user time:
# sa -l # sa --separate-times
10. To Print the number of processes and number of CPU minutes on a per-user basis:
# sa -m # sa --user-summary
11. To Sort the output by the number of calls:
# sa -n # sa --sort-num-calls
12. To Sort output items in reverse order:
# sa -r # sa --reverse-sort
13. To Merge the summarized accounting data into the summary files savacct and usracct:
# sa -s # sa --merge
14. To print the ratio of real time to the sum of system and user times:
# sa -t # sa --print-ratio
15. To print the userid and command name:
# sa -u # sa --print-users
16. To Print commands which were executed num times or fewer and await a reply from the terminal:
# sa -v 10 # sa --threshold 10
17. To see the version:
# sa -V # sa --version
18. To get the help:
# sa -h # sa --help
Summary
Overall, sa is a powerful tool for system administrators who need to monitor and analyze system resource usage. Its ability to generate detailed reports on user activity and system performance makes it a valuable tool for identifying potential performance issues and optimizing system resource usage. More information about sa, including usage examples, can be found on the sa manual page at https://manned.org/man/sa.8.