Marshall Kirk McKusick: Gunion: a new GEOM utility in the FreeBSD Kernel This talk describes the gunion(8) utility that was added to the FreeBSD kernel in February 2022. The talk starts with an introduction to the FreeBSD GEOM kernel layer describing its location and function. The talk then describes how gunion(8) tracks changes to a read-only disk using a writable disk. The talk concludes with examples of problems for which gunion(8) can be effectively used.

Marshall Kirk McKusick: Dr. Marshall Kirk McKusick's work with Unix and BSD development spans over forty years. It begins with his first paper on the implementation of Berkeley Pascal in 1979, goes on to his pioneering work in the eighties on the BSD Fast File System, the BSD virtual memory system, the final release of 4.4BSD-Lite from the University of California at Berkeley Computer Systems Research Group, and carries on with his work on FreeBSD. A key figure in Unix and BSD development, his experiences chronicle not only the innovative technical achievements but also the interesting personalities and philosophical debates in Unix over the past forty years.