A developer called Fred had pointed out the ZFS support for Grub was now GPL'd. The code could be used to add ZFS support to the kernel.

Alan Cox refuted this option arguing that any further implementation would contravene Sun's licensing policy. Cox had repeatedly asked Sun for permission to use the code, but without receiving a reply. He concluded on the Linux kernel mailing list that Sun wanted to appear to be open, but was not handing ZFS to Linus Torvalds as the filesystem was the only argument for continuing to use Solaris in data centers.

Boot loader expert H. Peter Anvin added that GRUB only supported a rudimentary ZFS read only driver. Kernel developer Christoph Hellwig considers even read only support for ZFS to be a benefit for the kernel. On the list he offered to provide mentoring support for its implementation, if somebody is prepared to implement the project.

Thanks to its competent volume management, Sun's ZFS is regarded as a sophisticated filesystem and it can handle large volumes of data thanks to 128 bit pointers. If needed, the filesystem can be dynamically scaled; it identifies and removes filesystem errors without major performance hits and supports freezing and cloning of sectors. Most of ZFS is still under the Sun Open Source License CDDL.