Instead of building our own ZFS RPMs in order to build our own Lustre packages and for testing, it makes sense to fetch (with cache) and use pre-built ZFS RPMs from zfsonlinux.org. Beyond the minor savings of reducing the building on our own systems, more importantly this ensures that the packages we are building (i.e. lustre-osd-zfs-mount and kmod-lustre-osd-zfs) will be based on exactly the same packages as what users will install.

This will also simplify the integration of Lustre with Linux distros that already include ZFS packages, such as Ubuntu 16.