This occurred on a SPARC MDS when an x86 client tried to "lfs setstripe" a new directory:

00000004:00000080:30.0:1367562225.034331:2800:27098:0:(lod_lov.c:850:lod_verify_striping()) bad userland LOV MAGIC: 0xd00bd10b

The number is exactly LOV_USER_MAGIC_V1 swabbed. The client code always send the lov_mds_md_v1 structures in little-endian, and the MDS code do no swabbing for the structures. This is problematic for x86 clients talking with SPARC servers.