FTP has been around since the early days of the internet. Even though it’s old and cranky a lot of sysadmins, especially those just getting into managing a server, still don’t know anything else. FTP is outdated, has a lot of problems and sometimes it can be outright dangerous, however it’s wide spread acceptance as an easy way for transferring files makes it hard to switch to alternative protocols. If you have a choice, don’t use it. I’ll show you why.
Defense against spam has always been a hassle. Statistical filters only get you so far and they consume a LOT of resources. For exactly that reason I like to employ basic checking policies before accepting e-mail at all. These policies have gotten me pretty far and my false positive rate is pretty low.
Ever so often I get to set up hosts for running PHP. When running a load balanced solution, you have more hosts and reading logs gets complicated, development gets tedious. So what helps, is a central logging server. This is pretty easy to set up with syslog-ng, however PHP has a annoying habit of logging everything with the NOTICE error level.
There are times, when we get an application and need to find out what it does fast. We don’t have the time to read the source code. Fortunately there are multiple tools to our rescue, one of which is the strace Linux utility. strace means system call trace, it shows us every system call the application does, such as opening or reading a file, writing data to a network socket. It’s not a magic pill, it won’t show the internal working of the application, but it’s still very useful to find out what it does externally (IO operations and such).
In September 2009 I created the big Exim tutorial consisting of 5 parts on the Hungarian Unix Portal. In January 2010, I transfered it to my Hungarian site. Now I’m translating it to English.