Lustre uses loadable plugins for mkfs/mount to support multiple back end types (mount_osd_zfs.so, mount_osd_ldiskfs.so). This allows for back end support to be vended out separately (in theory). In practice, this can lead to esoteric errors being output when the system isn't setup correctly.

The plugin system seems to have value. But it should output useful error messages and try harder to actually find the plugins. Otherwise, errors are hard to debug and the tools don't work well on different platforms. In particular, if I `sudo make install` openZFS - Lustre should be able to find the openZFS binaries.

This ticket will also cover some minor cleanups.