[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.
On April 23, IBM rolled out the long-awaited POWER8 CPU, the successor to POWER7+, and given the extensive pre-announcement speculation, the hardware itself was no big surprise (the details are fascinating, but not suitable for this venue), offering an estimated 30 - 50% improvement in application performance over the latest POWER7+, with potential for order of magnitude improvements with selected big data and analytics workloads. While the technology is interesting, we are pretty numb to the “bigger, better, faster” messaging that inevitably accompanies new hardware announcements, and the real impact of this announcement lies in its utility for current AIX users and IBM’s increased focus on Linux and its support of the OpenPOWER initiative.
OK, so we’re numb, but it’s still interesting. POWER8 is an entirely new processor generation implemented in 22 nm CMOS (the same geometry as Intel’s high-end CPUs). The processor features up to 12 cores, each with up to 8 threads, and a focus on not only throughput but high performance per thread and per core for low-thread-count applications. Added to the mix is up to 1 TB of memory per socket, massive PCIe 3 I/O connectivity and Coherent Accelerator Processor Interface (CAPI), IBM’s technology to deliver memory-controller-based access for accelerators and flash memory in POWER systems. CAPI figures prominently in IBM’s positioning of POWER as the ultimate analytics engine, with the announcement profiling the performance of a configuration using 40 TB of CAPI-attached flash for huge in-memory analytics at a fraction of the cost of a non-CAPI configuration.[i]
A Slam-dunk for AIX users and a new play for Linux
I said last year that this would happen sometime in the first half of this year, but for some reason my colleagues and clients have kept asking me exactly when we would see a real ARM server running a real OS. How about now?
To copy from Calxeda’s most recent blog post:
“This week, Calxeda is showing a live Calxeda cluster running Ubuntu 12.04 LTS on real EnergyCore hardware at the Ubuntu Developer and Cloud Summit events in Oakland, CA. … This is the real deal; quad-core, w/ 4MB cache, secure management engine, and Calxeda’s fabric all up and running.”
This is a significant milestone for many reasons. It proves that Calxeda can indeed deliver a working server based on its scalable fabric architecture, although having HP signing up as a partner meant that this was essentially a non-issue, but still, proof is good. It also establishes that at least one Linux distribution provider, in this case Ubuntu, is willing to provide a real supported distribution. My guess is that Red Hat and Centos will jump on the bus fairly soon as well.
Most importantly, we can get on with the important work of characterizing real benchmarks on real systems with real OS support. HP’s discovery centers will certainly play a part in this process as well, and I am willing to bet that by the end of the summer we will have some compelling data on whether the ARM server will deliver on its performance and energy efficiency promises. It’s not a slam dunk guaranteed win – Intel has been steadily ratcheting up its energy efficiency, and the latest generation of x86 server from HP, IBM, Dell, and others show promise of much better throughput per watt than their predecessors. Add to that the demonstration of a Xeon-based system by Sea Micro (ironically now owned by AMD) that delivered Xeon CPUs at a 10 W per CPU power overhead, an unheard of efficiency.