Not much is known at this time, and no source code has yet been released, but a post on the company blog from late October 2009 claims that they have a build of ZFS kernel code that is able to create file-backed zpools, create filesystems on those zpools, and mount them.

Approximately 2 weeks later, further information was made available from the company’s twitter account, where a November 15th tweet claims they can now create and delete files, and issue the Unix ls command, but that actual reads and writes do not yet work. This may seem contradictory, however it may be that the code for working with files in memory is functional, but that the code to commit those operations to disk is not complete.

It is surprising that it has taken this long for a Linux kernel driver for ZFS to (hopefully) appear, but the licensing issues may have given those with the technical ability to complete such a port, reason for caution. The license that covers the existing ZFS codebase from Sun, the CDDL, is known to be incompatible with the license that covers the Linux kernel, the GPL. Because of this incompatibility, the copyright holder of the main ZFS codebase (Sun Microsystems, soon Oracle Corporation) would need to relicense it for the code to be accepted into the mainline Linux kernel.

However, Knowledge Quest Pvt. Ltd. believes that so long as they only use kernel symbols that are not marked “GPL-only”, and only compile the code as a kernel module, they are safe legally. Time will tell if this strategy proves successful, but it would be similarly surprising if any legal action is taken, particularly since the code being ported is itself open source and released under an OSI approved license.