Sun Microsystems has updated the Logical Domain (LDom) server virtualization hypervisor for its Niagara family of servers, and used the occasion to brag about some benchmark results it has posted on a popular Java application test.
The LDom hypervisor is only available for Sun and Fujitsu servers based on Sun's Sparc T1, T2, and T2+ servers, which pack multiple Sparc cores with from four to eight threads each, into a single chip package.
These Sparc T series chips are available in single-socket and two-socket configurations that span a performance range that is roughly equivalent to entry and midrange x64 and RISC/Unix boxes.
The LDom hypervisor allows each thread on a Sparc T machine to be configured as a virtual machine, capable of running a complete instance of the Solaris 10 operating system, including its own Solaris kernel and file system.
The LDoms can also span multiple threads if customers want to dedicate more compute power to a partition. LDoms are distinct from Solaris containers, which offer a different kind of virtualization commonly called a virtual private server and that creates what looks like separate Solaris instances on a machine, but these instances run off a shared kernel and file system. This VPS approach makes patching and updating easier, but it does mean that all of the container eggs are in the same kernel/file system basket and are not fully isolated instances like LDoms allow.
The LDom software is available for free as a download through Sun's CoolThreads tool site, and the company is obviously pitching its software and its freeness against the various hypervisors available for x64 and other RISC/Unix platforms.
The company stretches the truth quite a lot, though, when claiming LDoms can save IT shops up to $10,000, considering that XenServer Enterprise is now free, VMware ESXi is free with $450 a year in support costs, and IBM has offered a base PowerVM license at $40 per processor core on its Power6 machines since early last year.
That said, LDoms appears to be a good technology, and it is exactly the kind of virtualization that Sun and Fujitsu need for their entire Sparc-based systems. It would be incredibly stupid if LDoms are not part of the future Rock UltraSparc-RK processors, expected in Supernova servers in the second half of this year.
With the LDom 1.1 hypervisor update, Sun has added "significant" but unquantified performance enhancements, and - more importantly for many Sparc shops - has a live migration feature called domain mobility.
This will allow the dynamic migration of domains within a machine and across a network of machines, to improve resiliency and for managing energy consumption on a group of servers. It does this by consolidating running LDoms onto the smallest number of physical machines and shutting down boxes that are not needed.
The LDom 1.1 update also includes virtual I/O dynamic reconfiguration, allowing virtual networks and storage to be added to a domain on the fly, without requiring a reboot of the LDom. The update also includes a feature called hybrid I/O for network interfaces, which lets a virtual network interface in a guest domain supporting Solaris to directly access a physical network interface in an LDom that has been set up to be a dedicated I/O domain. The updated hypervisor also includes support for VLANs adhering to the 802.1Q standard, and virtual disk failover.
As part of the LDom 1.1 announcement, Sun took a swipe at IBM's Power 570 AIX boxes based on their respective test results on the SPECjAppServer2004 benchmark. This test, created by the Standard Performance Evaluation Corporation, is meant to measure the performance of a system - or collection of machines - as Java application server.
Sun touted the 6,335 operations per second (OPS) performance it was able to get on a quad-socket T5440 server using 1.4GHz Victoria Falls Sparc T2+ chips and 128GB of main memory, a test it ran last October atop Oracle's WebLogic SE 10.3 application server and Solaris 10.
However, last month Sun ran the same SPEC test on four two-socket T5140 servers, each with 1.2GHz Sparc T2+ processors and with 32GB of memory, that was able to support 9,501 OPS on the SPECjAppServer2004 benchmark.
For fun, Sun picked on IBM's Power 570 server equipped with four 4.7GHz cores and running AIX and IBM's own WebSphere V6.1 app server, which delivered a mere 1,198 OPS on the same test.
Sun claimed it can consolidate up to four racks of IBM's Power 570 machines onto two T5440 servers at about one-fifth the hardware cost. It would take a long time to peel that claim apart, but suffice it to say Sun seems to be ignoring that IBM can now cram up to 32 cores in a single system image with the Power 570. It has been able to do this since last fall but could not do when it ran this SPECjAppServer2004 test back in August 2007 as its first Power6 machines launched.
I think it is time to look at some SPEC, TPC-C, SAP, and other tests and do a little more detailed analysis based on cost and form factor. Vendors game this stuff way too much. If none of you want to do it, I will. ®