• Linux,  Work

    Improving performance by using tmpfs

    Today I analyzed disk reads and writes on a server with iotop and strace and found some interesting possible optimizations. With iotop you can check which processes are reading and writing from the disks. I always press the o, p and a keys in iotop so that it only shows me processes doing I/O and so that it will show accumulated I/O instead of the bandwidth. With the left and right arrows I select on which columns to sort the list. Once you have identified the processes wich are doing much I/O, you can check what they are reading or writing with strace, for example # strace  -f -p $PID …

  • Linux,  Work

    Flash and Java: the end of obsolete technologies

    Already for a long time, I am a total opponent of Flash and things are clearly not improving. Quite on the contrary: Flash is still unstable on my systems, often not working correctly or causing browser hangs and it has many serious security flaws, which are fixed rather slowly by Adobe. Another piece of technology which is annoying is Java. Java is a serious memory hog, does not integrate very well in Linux distributions (no centralized package management system for the gazillion of Java libraries and frameworks), and Java’s new owner, Oracle, is trying to make Java a patent minefield by suing Google. Recently, Oracle also decided to publish a…

  • Linux,  Work

    Migrating from Microsoft SQL Server to PostgreSQL

    One of the servers I manage at work is still running Microsoft Windows 2000. This system is hosting a few old forgotten web sites and it runs Microsoft SQL Server containing a few databases still in use. This server was already there when I started working at the university. Fortunately I never had to do much work on it and there never was a serious crash: it would have been a serious headache for me restoring this system because I do not have much knowledge about Windows and SQL Server. During some spare time at work I decided taking a look at migrating the MS SQL Server databases to PostgreSQL.…