How can I run the sar command to run daily using cron then get killed every 24 hours and start over again creating a new log file?
Command:
sar -u 300 288 >> $(date "+ %Y-%m-%d")-cpu.log This will log usage every 15 minutes for just over 24 hours.
Would this be a proper bash script?
#!/bin/bash # Kill current process kill sar # Start new sar sar -u 300 290 >> $(date "+ %Y-%m-%d")-cpu.log On most linux distros (if not all), sar already saves that data in a file in /var/log.... Have look at -o in man sar to find the exact path:
-o [ filename ] Save the readings in the file in binary form. Each reading is in a separate record. The default value of the filename parameter is the current daily data file, the /var/log/sysstat/sadd file. The -o option is exclusive of the -f option. All the data available from the kernel are saved in the file (in fact, sar calls its data collector sadc with the option "-S ALL". See sadc(8) manual page). You can read that binary file using sar -f filename.
If you really need to take care of the data collection process, check man sadc.
sar >> logfile executed by cron everyday at 23:52. sar without interval or count, it works more like cat. It writes to standard output and terminates, so you have no process to kill... If you're running it with count, it will just stop after it finishes counting. Try running sar and sar 2 2 to see the difference.