[Apologies to all who have just read this post with a sense of deja-vue. I saw a typo, corrected it and then republished the blog, and it reset the publication date. This post was originally published several months ago.]

Having been away from the Linux scene for a while, I recently took a look at a newer version of Linux, SUSE Enterprise Linux Version 11.3, which is representative of the latest feature sets from the Linux 3.0 et seq kernel available to the entre Linux community, including SUSE, Red Hat, Canonical and others. It is apparent, both from the details on SUSE 11.3 and from perusing the documentation on other distribution providers, that Linux has continued to mature nicely as both a foundation for large scale-out clouds as well as a strong contender for the kind of enterprise workloads that previously were only comfortable on either RISC/UNIX systems or large Microsoft Server systems. In effect, Linux has continued its maturation to the point where its feature set and scalability begin to look like a top-tier UNIX from only a couple of years ago.

Among the enterprise technology that caught my eye:

  • Scalability – The Linux kernel now scales to 4096 x86 CPUs and up to 16 TB of memory, well into high-end UNIX server territory, and will support the largest x86 servers currently shipping.
  • I/O – The Linux kernel now includes btrfs (a geeky contraction of “Better File System), an open source file system that promises much of the scalability and feature set of Oracle’s popular ZFS file system including checksums, CoW, snapshotting, advanced logical volume management including thin provisioning and others. The latest releases also include advanced features like geoclustering and remote data replication to support advanced HA topologies.
  • Virtualization – The 11 series kernel includes containers, a lightweight virtualization abstraction similar to Solaris Containers and Resource Zones. This provides a virtualized OS image that has very low overhead, and (both a great strength and a great weakness, depending on use case) generates all virtual OS Images from a single root OS image, so there is only one set of files to update to patch all OS Images.
  • Clustering and HA – Supported by file replication features,    the latest kernel distributions include the ability to set up geographically distributed clusters of physical and virtual servers with either automated or manual failover.
  • IBM Power support – Not surprising, considering SUSE’s strong history with IBM, SUSE 11.3 also contains a number of extensions and capabilities tied to IBM’s Power systems. In volume terms probably not an earth-shattering development, but it should put them in good shape for competing for future revenues on IBM’s Power series, including their very competitive Linux-only offerings.

In summary, modern Linux is looking an awful lot like UNIX, and the latest round of capabilities gives it many of the high-end features that have distinguished enterprise-grade UNIX variants such as Solaris and AIX as little as three years ago. While both Oracle and IBM have continued to invest, and have added further features to their UNIXs that offer differentiation from Linux, the difference is shrinking, and the number of workloads that cannot be effectively served by Linux on x86 systems continues to shrink. Given time for the new distros to prove their stability, the future is bright for Linux as a peer for large and critical enterprise workloads.