tar.xz file

tar.xz file

# xz -d linux-3.1-rc4.tar.xz

#tar xvf  linux-3.1-rc4.tar

If you don't have xz program, download xz-5.0.3.tar.bz2

http://download.chinaunix.net/download/0014000/13078.shtml

#tar -xf xz-5.0.3.tar

#cd xz-5.0.3

#./configure

#make

#make install