> I never exactly understood what's the problem related to ZFS' adoption in Linux (problem related mainly to the ARC algorithm?). The problem with ZFS adoption

> I never exactly understood what's the problem related to ZFS' adoption in Linux (problem related mainly to the ARC algorithm?). The problem with ZFS adoption in Linux is copyright, not patents. The license used by the ZFS code and the license used by the Linux kernel are incompatible, so one cannot distribute the combination of both without violating one of the licenses. This means that the ZFS code cannot be incorporated in the Linux kernel, so it's doomed to forever stay out-of-tree. This could in theory be worked around by a clean-room reimplementation of the ZFS code, keeping the same filesystem format, but I suppose most people who could do that work either are already working with the ZFS code, or find it more interesting to create their own filesystem. It would also be a lot of work, and take a long time until the reimplementation would be considered stable.