“Your company appears to be shipping kernel features in RTS OS that are not made available under the GPL, specifically support for the EXTENDED_COPY and COMPARE_AND_WRITE SCSI commands, in order to claim full Vmware vSphere 5 VAAI support.”
RTS:“In fact, we are not violating GPL. In short, this is because we wrote the code you are referring to (the SCSI target core in our commercial RTS OS product), we have exclusive copyright ownership of it, and this code contains no GPL code from the community. GPL obligations only apply downstream to licensees, and not to the author of the code. Those who use the code under GPL are subject to its conditions; we are not.
As you know, we contributed the Linux SCSI target core, including the relevant interfaces, to the Linux kernel. To be clear, we wrote that code entirely ourselves, so we have the right to use it as we please. The version we use in RTS OS is a different, proprietary version, which we also wrote ourselves. However, the fact that we contributed a version of the code to the Linux kernel does not require us to provide our proprietary version to anyone.”
From RTS’ site:“The RTS storage software stack is based on the open-source LIO Unified Target stack in Linux, which is an emerging industry standard with a vivid and growing community. Join the rising tide!”
I don’t know all the details but it looks to me that RedHat has a case. RTS appears to be wanting to have its cake and to eat it too. “based on” makes the stuff seem like a derivative work… Having a FLOSS and non-FLOSS version of software seems rather foolish to me. Either you’re distributing FLOSS or you’re not. Why do both? RTS could just as well charge as much to those who profit from using the software. Having a foot on the boat and on the dock at the same time is dangerous as I learned years ago, travelling in the North.