Microsoft has revealed that its forthcoming Windows Server Virtualization technology would ship without a key performance feature designed to help it compete with rival VMware.
In addition, Microsoft said the first public beta of Windows Server Virtualization (WSV), code-named Viridian, will ship when Longhorn Server is released to manufacturing (RTM) in the second half of 2007. The RTM designation means development is complete and all that remains is to create media for distribution of the bits.
The bigger news, however, is that to meet the WSV timeline Microsoft is eliminating three features, including Live Migration, which lets users move virtual machines between individual WSV instances without any downtime.
"An important point is that we are postponing these features until a future release," says Patrick O'Rourke, senior product manger in the Windows Server division at Microsoft.
The other two cut features are the ability to hot-add resources, such as storage and memory, and a reduction to the limit of the number of processors supported from 64 to 16.
The Live Migration feature, however, stands out because it provides performance guarantees for dynamic workloads and helps balance loads to minimise the number of active servers.
Critics of Microsoft's current Virtual Server software often cite its lack of live migration capabilities as one reason it is not ready to support performance sensitive or critical applications.
"Cutting Live Migration is a big deal," says Peter Pawlak, an analyst with independent research firm Directions on Microsoft. "This is something they have been saying they would be able to do and it was a big feature in order to have parity with VMware and now they are saying they cannot do that. It is one thing they really need to be able to do."
Observers say the elimination of Live Migration likely means Microsoft is struggling with development of its next-generation virtualisation technology and the company realises it must get virtualisation right out of the gate to compete effectively with established industry leader VMware.
Pawlak says it’s hard to understand what’s going on with WSV and Microsoft isn't telling the whole story.
"It could well be that they are finding out this is harder than it looks," Pawlak says, "but what I think is that Microsoft realises how important it is to get this right and that they can't botch it given the situation with VMware. So Microsoft is getting ultra-conservative. They likely want to do a lot more testing and they know they can't fast track this stuff."
Mike Neil, general manager of Microsoft's virtualisation strategy, once again used his blog to broadcast the news on the feature cuts.
In February he used the blog to tout Live Migration as a key to WSV's manageability, writing that WSV includes some innovative functions such as Live Migration that offer users "flexible and dynamic deployment options for all their workloads”. Neil also wrote that Microsoft's intent was to make "Windows the most manageable virtualisation platform."
Without Live Migration in the first release of WSV, which is slated to ship within 180 days of Longhorn Server, critics say the manageability issue will be a tough sell to users.
Live Migration also is supported in the forthcoming release of System Center Virtual Machine Manager (SCVMM), slated for the second half of this year. SCVMM helps maximise physical server utilisation, and centralise management and provisioning of virtual machines. It includes integration with the Live Migration feature to support automatic virtual machine migrations.
In terms of the public beta availability of WSV, Microsoft did not make it any clearer when the software will be available. Last month, Microsoft delayed the first public beta of WSV from the first half of 2007 until the second half, but did not offer any concrete ship dates.
Thursday's announcement does not nail down the ship date any further because it is still officially pegged as "the second half of 2007”.
Rumours floating around put Longhorn Server shipment anywhere from September to early 2008. RTM is typically announced six to eight weeks before general availability.
Microsoft officials, however, did note that having the WSV beta and Longhorn Server ship together would let users test the two together.
Microsoft said on a version of SCVMM for WSV will be made available 60 to 90 days after the public beta of WSV ships.