How to Monitor Your Linux Performance With Sysstat

1. How do I know if Sysstat is running?
2. How do I see performance in Linux?
3. How install SAR Linux?
4. How do I start Sysstat service?
5. How do I see memory usage on Linux?
6. How do I find bottlenecks in Linux?
7. What is causing high load average Linux?
8. Where is SAR files in Linux?
9. What is sar command?
10. What is Iowait in SAR output?
11. How do I enable SAR data collection?
12. How do I reduce memory usage in Linux?
13. Does free memory exist on Linux?
14. How do I clean up Linux?

How do I know if Sysstat is running?

View Running Process Resource Utilization

Using pidstat command with switch -d provides you details of currently running processes on systems. Also try pidstat with -r to show resource utilization by processes on every 1 second for the 5 times.

How do I see performance in Linux?

1. How To Check CPU Usage from Linux Command Line. top Command to View Linux CPU Load. mpstat Command to Display CPU Activity. sar Command to Show CPU Utilization. iostat Command for Average Usage.
2. Other Options to Monitor CPU Performance. Nmon Monitoring Tool. Graphical Utility Option.

How install SAR Linux?

Installing sar

1. Install the sysstat package using the following command for a Debian-based distribution: # sudo apt-get install sysstat. ...
2. Edit the /etc/default/sysstat file with your favorite text editor and change the following value from: ENABLED="false" ...
3. Restart the sysstat service using the following command:

How do I start Sysstat service?

Start sadc/sar by using the sysstat service. When started as a service, the data files are written to the /var/log/sa directory. The files are named sa <dd> and sar <dd> respectively, where <dd> is the current day's two-digit date. Both files are constantly updated during the day.

How do I see memory usage on Linux?

5 commands to check memory usage on Linux

1. free command. The free command is the most simple and easy to use command to check memory usage on linux. ...
2. 2. /proc/meminfo. The next way to check memory usage is to read the /proc/meminfo file. ...
3. vmstat. The vmstat command with the s option, lays out the memory usage statistics much like the proc command. ...
4. top command. ...
5. htop.

How do I find bottlenecks in Linux?

We can find bottleneck in linux server performance using following method..

1. Take the output of TOP & mem, vmstat commands in one notepad.
2. Take sar output of 3 months.
3. check the variation in processes & usage at the time of implementation or change.
4. If the load is unusual since the change.

What is causing high load average Linux?

If you spawn 20 threads on a single-CPU system, you might see a high load average, even though there are no particular processes that seem to tie up CPU time. The next cause for high load is a system that has run out of available RAM and has started to go into swap.

Where is SAR files in Linux?

sar historic data is stored in /var/log/sa directory in case of RedHat based distributions. Files are simply binary formats containing sar data for each retained date.

What is sar command?

SAR stands for System Activity Report, as its name suggest sar command is used to collect,report & save CPU, Memory, I/O usage in Unix like operating system. SAR command produce the reports on the fly and can also save the reports in the log files as well.

What is Iowait in SAR output?

Following is the definition taken from the sar manpage: %iowait: Percentage of time that the CPU or CPUs were idle during which the system had an outstanding disk I/O request. Therefore, %iowait means that from the CPU point of view, no tasks were runnable, but at least one I/O was in progress.

How do I enable SAR data collection?

Check the man pages starting with man sar . Also there should be documentation in /usr/share/doc/sysstat . sar can be used to collect and display current data even if the historical data is not available. Check to see if there are any files in /var/log/sa , If there are then data is being collected.

How do I reduce memory usage in Linux?

How to Clear Cache in Linux?

1. Clear PageCache only. # sync; echo 1 > /proc/sys/vm/drop_caches.
2. Clear dentries and inodes. # sync; echo 2 > /proc/sys/vm/drop_caches.
3. Clear PageCache, dentries and inodes. # sync; echo 3 > /proc/sys/vm/drop_caches. ...
4. sync will flush the file system buffer.

Does free memory exist on Linux?

Free memory does exist on linux. ... The kernel can trivially free more memory by deleting pages from the buffer cache, which is very inexpensive if they don't need to be written back to disk first.

How do I clean up Linux?

Terminal commands

1. sudo apt-get autoclean. This terminal command deletes all . ...
2. sudo apt-get clean. This terminal command is used to free up the disk space by cleaning up downloaded . ...
3. sudo apt-get autoremove.