Tuesday, October 29, 2013

Standalone server reporting with Sar and KSar

Zabbix is a great tool for monitoring and reporting for multiple servers and that installation is covered here. In this instance, Sar and KSar will be used as a standalone data collection tool, as it falls outside the physical and networking reach of my Zabbix server.

Sar is a neat little tool that is part of the sysstat package, more information can be found on the author's website. In my case, we will be using to collect data on CPU, Memory, Swap, Network and all the other metrics that can make or break a Linux based service.

kSar is a separate java based tool that generates some lovely graphs using the collected sar data, because a picture paints a thousand words, or in this case, a graph summarizes a crapload of data.

This tutorial covers the installation of both, as well as a practical usage scenario.

0. Got root/ sudo?

1. Install the packagesyum install sysstat java

2. Set the sysstat cron to run
nano /etc/cron.d/sysstat
Ensure the following lines are active / not commented out. The first line specifies how often the tool should take a snapshot, the second is when the daily summary is processed.

*/10 * * * * root /usr/lib/sa/sa1 1 1
53 23 * * * root /usr/lib/sa/sa2 –A

3. Configure sar to keep a month's worth of data

By default, sar keeps 7 days worth of data. Since we need data monthly, the configuration needs updating.

nano /etc/sysconfig/sysstat

Update line, HISTORY = 7 to now read:

4. Download kSar

Located at http://sourceforge.net/projects/ksar
Create a folder to store kSar and Monthly text files
mkdir /mon
Extract kSar into /mon
Change permissions to make kSar executable
chmod +x /mon/kSar

5. View Daily Server Data (default)
Prep report:
LC_ALL=C sar -A > /mon/sardata.txt

See the graphs
cd /mon/kSarx.x.x/

Click "Data" Menu option -> Load from text file
Select /mon/sardata.txt

6. View Monthly Server Data (see below for actual script)

Prep report:
cd /mon/
(Ensure script is executable before running!)

See the graphs
cd /mon/kSarx.x.x/

Click "Data" Menu option -> Load from text file
Select /mon/sarmonthly_July.txt (use appropriate month name)

7. All done!

#cleanup old monthly file
rm -rf /mon/sarmonthly_$(date +"%B").txt
#loop through 31 possible days, merge all files into one
for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31; do
LC_ALL=C sar -A -f /var/log/sa/sa$i >> /mon/sarmonthly_$(date + "%B").txt


That's it! Til next time...