iptables debugging
29. March 2013

Sometimes packets leave their line or get lost passing an iptables firewall. Even if you know what you do, there might be a typo or a single mistake in you iptables rules, driving you crazy. As I had to learn in the past years, there are several ways to see what’s going on. Logging blocked […]

MySQL Performance
22. March 2013

IO Performance measurement with bonnie++ To have a look at the performance, your storage devices has, bonnie++ is quite well. To write a file of 16 GB and see how fast it is, just do: sudo yum install bonnie++ cd /<destination> sudo bonnie++ -s 16000 Top for MySQL Sometimes it is quite nice to have […]

Linux Shell – some hints
1. February 2013

Search search for string in files recursively grep -R “Suchstring” * ┬ásearch for string in stdout cat /var/log/syslog | grep ‘ERROR’ ┬ácount lines in output cat /var/log/syslog | grep ‘ERROR’ -c search for a file┬árecursively find . -iname “” search and replace string in multiple files (replace bike with car in all html files in […]

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