Operating Systems

Linux on System z: Red Hat vs. The Blob

Callout: Efforts are under way to merge the OpenSolaris for System z port into the mainline Illumos tree and keep it alive as an alternative to Solaris 10.

Recently, it’s been quiet in the enterprise Linux world—lots of tinkering and experimenting, but nothing really newsworthy on the user side. On the kernel and utility developer side of the world, however, there are a couple of items that may prove interesting.

First, Red Hat is changing the way its contributions are submitted to the kernel source tree. Previously, Red Hat used the traditional model of one contribution, one patch, allowing other developers to easily see (and reference) individual changes to view what comprised a shipped Red Hat kernel. Due to some less-than-savory actions by a competitor, Red Hat has decided to no longer submit individual patches but use a monolithic patch per kernel release, bundling everything into one giant, opaque blob of a patch file and removing the individual patch references and detail documentation for that giant patch. While this will work, allowing people to still build a Red Hat “distribution” kernel, it does add a lot of footwork to the process, slowing down the production of CentOS distributions and other distributions that track Red Hat development. It’s unclear what the other ramifications might be for the future of kernel development, but it’s certainly a sign of the impact of the commercialization of the enterprise Linux marketplace and how that will affect future work for employees of companies that manufacture and sell Linux distributions.

Second, the Fedora developers have brought System z into the fold as a supported platform. Fedora 14 seems to be stable and useful, and has considerably more modern RPM versions of most software that has become common on the Intel platforms from the ones shipped with RHEL or CentOS. While this isn’t necessarily interesting from the production system space, it does provide users an alternative for building and testing newer software and builds before the new interfaces and Application Programming Interfaces (APIs) trickle down to the RHEL distribution and its derivatives. The System z files can be found with the other Fedora releases at www.fedora.org.

Last, a worrying change with OCFS2. The current release of OCFS2 (the most commonly used cluster file system for Linux on System z) isn’t yet supported on either major Linux distribution. Notices on Oracle’s Website state that OCFS2 version 1.6 will be available only on Oracle’s Unbreakable Linux, which isn’t available for System z. It appears likely the major distributors will build and provide RPMs for the System z distributions, but it seems an unpleasant start to Oracle’s cooperation strategy with the open source community. I’d encourage System z users to use their contacts with Oracle to comment on this change of heart.

With all these changes, the question of what happens next when dealing with Oracle may generate some new life for Illumos and the OpenSolaris port for System z, as well. Efforts are under way to merge the OpenSolaris for System z port into the mainline Illumos tree and keep it alive as an alternative to Solaris 10. Watch this space for more details.

In closing, the conference and convention season is well under way, and we’re looking forward to seeing more new announcements and developments in the coming months.