To build openafs, kernel headers are recommended to be installed (so configure can detect the local sysname). On SL5, as root do a
yum install kernel-devel
and you're set (for the time being).If there's still no /usr/src/linux:
ln -s /usr/src/kernels/2.6.18-92.1.10.el5-i686 /usr/src/linux
...or whatever directory the kernel source was installed to.
In the openafs-version directory:
mkdir `sys` cd `sys` ../configure --prefix=/usr --libdir=/usr/lib --bindir=/usr/bin --sbindir=/usr/sbin --with-krb5-conf --enable-bitmap-later --enable-bos-restricted-mode --enable-fast-restart --enable-bos-new-config --enable-supergroups --enable-transarc-paths --enable-object-storage --enable-osd-policies