On the Operations Manager 2012 Release Candidate download page there is a file named Microsoft.Unix.ShellCommand.Library.exe. The description of this package is

UNIX/Linux Shell Command Template Management Pack
This Management Pack implements authoring templates that allow the creation of rules, tasks, and monitors based on execution of shell commands on UNIX/Linux agents

If you download this file, extract it and import the management pack you will see some new features in the console

Of course this is a fantastic tool for us Operations Manager administrators. In March 2009 I wrote a blog post how to monitor a logfile on Linux, Logfile Check on Linux. The scenario was to monitor a file size. The challenge was that we first needed to use a bash script to check the file size, if the file size was above the threshold we wrote a warning to a logfile. The script was triggered by a cron to run every X minute. Then we used default features in OM 2007 R2 to monitor the logfile. That was the solution in 2007 R2. Cron > bash script > logfile > Operations Manager 2007 R2.

Now, with this new feature in Operations Manager 2012 we can run the script direct from a monitor, send back the result and control the status of the monitor. To do the same as we did in the blogpost from March 2009, but with Operations Manager 2012, follow these steps

1. In the Operations Manager console, navigate to Author/Management Pack Objects/Monitors
2. Right-click monitors and create a new Unit Monitor, select Scripting/Generic and UNIX/Linux Shell Command Two State Monitor
3. Select a management pack
4. General, input a name and a monitor target. For example “Field – X plat – File Size” as name and “SUSE Linux Enterprise Computer” as monitor target
5. Schedule, select how often you need to monitor to check the file size, for example very 15 minute
6. Shell Command Details, input the script you want to use. The command can be a path to a binary or script file or a single-line shell command. In this example we are looking at the script.sh file, if it larger than 4
   s=$( stat -c %s /root/script.sh); if [ $s -gt 4 ]; then echo $s Error; else echo “Ok”; fi;
7. Error Expression, use the default parameter name and configure “Operator Contains Error”
8. Healthy Expression, use the default parameter name and configure “Operator Contains Ok”
9. Configure Health, use default settings
10. Configure Alerts, check “Generate alerts for this monitor”. Input a alert description. In this example I have insert WS-Man data as a variable
    
11. Click OK and your monitor is ready!

When the file size is about the threshold, in this script example that is 4, you will get an alert looking like this

As I friend of mine would say, “That is pretty much Ninja!” 🙂