Let's create some load

Right, so we configured e-mail sending. But it's not so interesting until we actually receive some notifications. Let's increase the load on our test system. In the console, launch this:

$ cat /dev/urandom | md5sum

This grabs a pseudorandom, never-ending character stream and calculates its MD5 checksum, so system load should increase as a result. You can observe the outcome as a graph—navigate to Monitoring | Latest data and click on Graph for our single item again:

Notice how the system load has climbed. If your test system can cope with such a process really well, it might not be enough—in such a case, you can try running multiple such MD5 checksum calculation processes simultaneously.

Allow 3 minutes to pass and there should be a popup in the upper-right corner, accompanied by a sound alert:

There is one of the frontend messages we enabled earlier in our user profile. Let's look at what is shown in the message window:

• The small grey rectangle represents trigger severity...