Sun employee Jeff Bonwick, who is viewed as the inventor of the Sun filesystem, ZFS, published images of himself and Linus Torvalds enjoying a beer in his blog under the heading "Casablanca". The photos are accompanied by three short captions. But they have caused a storm by referring to a peanut butter TV ad. The claim "Chocolate on my peanut butter" advertised that both were included in a single bar. The same thing could apply to the combination of the kernal and ZFS. Bonwick concludes by saying: "All I can say for the moment is... stay tuned."

Open Solaris manager Jim Grisanzio provided another clue that the talks concerned ZFS. He titled an entry in his blog "ZFS Pics" thus firing the rumors before backpedaling and claiming that he had only chosen the title because the photos showed Bonwick and because he was a major contributor to ZFS development.

ZFS is a highly scalable 128 bit system that combines the meta filesystem with volume management abilities and is thus capable of creating software raids, for example, with little overhead. The system also offers high performance handling of very large files and data volumes. Simple administration is also a major advantage; thanks to a high level of automation it only needs a few, simply structured commands but still offers administrators a manual option. The community pages at opensolaris.org provide an overview of ZFS.

The explosive nature of this topic has its origins in the connection between ZFS and the kernel. Thus far there has been no cooperation although both are released under Open Source licenses. While the kernel is licensed under the GPLv2, Sun chose the Common Development and Distribution License (CDDL) for ZFS and for its Open Solaris operating system. The two licenses are incompatible. Besides being used in Open Solaris and Solaris 10, ZFS has been ported to FreeBSD and Mac OSX thus far. A project that supports use of the filesystem on Linux is ZFS on FUSE.