Rackspace Cloud and Slicehost Kernel Source Download Location
Working on a Rackspace Cloud or Slicehost server there are many times when there may be a need to have the kernel source for compiling different applications, currently the kernel source is publicly available. Here is the current url to download kernel sources from. http://kernel.slicehost.com/
Here is a write up on how to use the kernel source with Asterisk by installing Dahdi, which will not install without the kernel source. This method can also be applied to other applications that require the kernel source.
wget http://kernel.slicehost.com/18.104.22.168-rscloud/patched_source/22.214.171.124-rscloud.tar.gz mkdir /usr/src/kernels/ tar xzf 126.96.36.199-rscloud.tar.gz -C /usr/src/kernels/ cd /usr/src/kernels/188.8.131.52-rscloud/ zcat /proc/config.gz > .config make oldconfig && make modules_prepare
Once that has been done now it is possible to compile Dahdi, this is assuming you have already downloaded and unpacked the dahdi source, therefore are ready to compile.
cd /usr/src/dahdi-source KSRC=/usr/src/kernels/184.108.40.206-rscloud/ make KSRC=/usr/src/kernels/220.127.116.11-rscloud/ make install