The OpenSolaris project and Sine Nomine Associates have announced that Sirius - a Solaris port for IBM mainframes - is ready for action.

The Sirius variant of Solaris runs atop IBM's z/VM operating system, which is also one of the pioneer virtualization environments for servers. The Sirius code is a 64-bit implementation of Solaris that runs on z9 or z10 mainframe processors and requires z/VM 5.3 or later.

z/VM is one of the ways that IBM and its partner commercial Linux distributors - Red Hat and Novell - support Linux on the mainframe. But Linux also runs natively on top of the Processor Resource/Systems Manager (PR/SM) hypervisor that is nearly two decades old and that supports z/OS, Linux, z/VM, z/VSE, and TPF operating systems.

PR/SM is a hybrid hardware-software virtualization hypervisor that is a mix of microcode based largely on earlier versions of the VM platform for mainframes and hardware-assist features that have been part of the mainframe iron since PR/SM was announced in 1989.

Sine Nomine is the mainframe consultancy that has done the bulk of the work on Sirius. Last year, when I talked to the company about the project, it said that porting an operating system to PR/SM is particularly difficult, and that's why Sirius is taking the z/VM route to the mainframe. Moreover, PR/SM tops out at a mere 60 partitions per mainframe, while z/VM can have thousands of partitions and span up to 8 TB of main memory and 32 processor cores in a single partition.

You can get the Sirius binary code through Sine Nomine's Web site and the open source code through the OpenSolaris site, which is where development for OpenSolaris for x64 and Sparc processors as well as the related "Polaris" project for Power-based machines is hosted. A prototype of OpenSolaris running on mainframes was announced a year ago, by the way.

While IBM and Sun announced an OEM agreement in August 2007 that had IBM embrace Solaris and sell support contracts for it on selected models of its System x rack and BladeCenter blade servers and Big Blue gave the nod to the mainframe and Power ports, neither Sun nor IBM have made any big moves to get Polaris and Sirius rolled up into a commercially supported variant of Solaris 10.

Sine Nomine has been at this Solaris-on-the-mainframe thing for a while. The company did a feasibility study looking at moving OpenSolaris to the mainframe in 2005, before Sun even went open source with the code. Right after Sun put out the OpenSolaris source code, Sine Nomine created a project for the mainframe port, but serious development did not begin until November 2006. The company went public with the effort in April 2007, but it really didn't come to anyone's attention in the larger IT space until Sun and IBM inked their OEM agreement last August. ®