Things I learned last week (2)

Debian packages without repository

There is probably a better way to do that, but here is a command that display all the installed packages that are not part of a configured repository:

apt-show-versions -a |grep "No available version in archive"

These can be packages that are installed directly using dpkg -i, but I was surprised to find that many of them were in fact packages from repositories that I removed from my configuration. The problem is that without a repository there is no way to receive the new versions, which can be a problem when a security problem is discovered. Most of these packages were not used, but it is bad idea to keep obsolete stuff around – a malicious script can still try to call code from obsolete packages in the hope that an unpatched security bug can be exploited.

Android build still requires Sun Java

For the reasons explained above, I removed the sun-java6-jdk package from my system, but that made the Android build fail, which means that Android still requires the Sun JDK 1.6 (openjdk does not work) for its build, which is kind of crazy knowing that this package is no longer maintained. Even the Android web page is wrong as Ubuntu also no longer carry this package. I first tried to rebuild the package using make-pkg, but I stopped when I saw that registration is now required to download the JDK from Oracle. Finally I found that sun-java6-jdk was still available in the oldstable Debian repository, but for how long?

Here’s the line to add to /etc/apt/sources.list:

deb oldstable main contrib non-free

Asus KCMA-D8 Sensors

One of the reasons I built a new computer is because the previous one was overheating even under moderate CPU load, so I wanted to be sure that the new computer would be able to to sustain continuous load without crashing. Because my system uses a RAID array, I wanted to do the testing with Debian Live instead of the target OS. The problem was that the sensors were not displayed at all, and it took multiple hours of research (even using an I2C monitor to find out the address of the sensors chip) to finally find the reason: The PIIX4 chip has in fact 2 SMBus, but the second bus (which is the one connecting the chip managing the sensors) was not implemented in the Linux kernel version 3.2. After switching to a version 3.9 kernel the sensors were finally accessible, which showed that the north bridge was overheating. I installed a fan on top of the heatsink and now the north bridge temperature is under control and cpuburn tests shows that that new system does not overheat or crash even after one hour with the 12 cores used at 100%.

KVM and Virtualbox

Another reason for a new computer was to be able to use kvm to run the Android emulator at decent speed. But it seems that it is not possible to run a kvm application and virtualbox at the same time.
This means that I will not be able to run an Android app and its server in a virtualbox, so I’ll have to convert my servers to kvm.

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