VirtualBox 4 – Performance Problems Solved

For a current project I am working on, I need several Linux machines running simultaneously, in order to perform some test-runs. Further more, I need a Windows 7 installation, because I have to use some software only available for Microsoft Systems. Therefore, the virtualization solution VirtualBox, is quite handy to manage all of systems. Although my host system is not really state of the art ( Dual-Core E5200 @ 2.50GHz , 6GB RAM), the system performs quite nicely with several guests up and running at the same time. Only if I would perform complex tasks within a Linux guest, such as compiling software from source, the whole system would freeze and be unusable until a reset. After googeling for a while, I found a solution to this problem. The trick is to set the kernel option nohz=off in the GRUB boot menu file, you can find in /boot/grub/menu.lst. Open this file as root user and locate the record of your current kernel. Simply add the before mentioned option to this line and reboot the host system. The complete kernel boot section should no be similar to this one here:

title Ubuntu 10.10, kernel 2.6.35-28-generic-pae
uuid 94e1022f-4ffd-4825-b8ca-2e86eca07d10
kernel /boot/vmlinuz-2.6.35-28-generic-pae root=UUID=94e1..d10 ro quiet splash
nohz=off
initrd /boot/initrd.img-2.6.35-28-generic-pae
quiet

After I added this option, the system behaved much better and did not freeze anymore.

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