Does the PVFS client require a patched Linux kernel?
No. The kernel module source included with PVFS is generally targeted toward the official “Linus” kernels (found at kernel.org). Patches for the PVFS kernel module code may be provided for major distributions that have modified their kernel to be incompatible with the officially released kernels. The best place to find out more information about support for a kernel tied to a particular distribution is on the PVFS2-developers mailing list.