If you have to dig in to logs files to investigate a problem, 1: you have failed straight away but i won’t go in to that now, 2: if you have to look at them it helps if the log files are readable.

The icinga.log file has a lot of data and unfortunately the timestamps are in epoch time format.

[1411724135] SERVICE ALERT: monitor1.gb1;IOSTAT_BUSY;WARNING;HARD;5;WARNING:sda=O:5,W:0,C:0: sdb=O:4,W:1,C:0: 

Using a little perl command line magic we can convert that ugly timestamps into something more readable.

[Fri Sep 26 09:35:35 2014] SERVICE ALERT: monitor1.gb1;IOSTAT_BUSY;WARNING;HARD;5;WARNING:sda=O:5,W:0,C:0: sdb=O:4,W:1,C:0:

Just use…

perl -pe 's/(\d+)/localtime($1)/e' icinga.log |grep monitor1.gb1

or...

tail -f icinga.log | perl -pe 's/(\d+)/localtime($1)/e'