On x64 Windows, you've got 16 terabytes of address space, so why not use it?

Aug 10, 2007 07:57 GMT  ·  By

If there was still any amount of doubt left in you that virtualization represents the future, then scratch it off completely. And in this context, you can use as argument the capabilities introduced by Microsoft's own hardware emulating technologies. Now, the Redmond company is by no means a leader on the virtualization market. Still, both Virtual PC 2007 and Virtual Server R2 SP1 are available for download free of charge, a detail that in itself recommends Microsoft virtualization products. Still, while Virtual PC 2007 is reserved for the client side, and client operating system, Virtual Server R2 SP1 addresses server operating system and enterprise scenarios. And in combination with the x64 edition of Windows Server 2003, Virtual Server R2 SP1 will work wonders.

"Virtual Server 2005 R2 SP1 running on Windows Server 2003 64-bit (x64 editions). Virtual Server 2005 R2 SP1, now supports up to 256 GB of physical memory and we upped the limit to 512 running virtual machines when running on Windows Server 2003 x64 Editions. Please note that the limit of 64 running virtual machines is unchanged when running on 32-bit (x86) Windows Editions," revealed Jeff Woolsey, a Senior Program Manager at Microsoft on the Windows Virtualization Product Group Team.

In this regard, it is important to understand the evolution from Virtual Server 2005 R2 and Virtual Server 2005 R2 Service Pack1. Virtual Server 2005 R2 running on either Windows Server 2003 32-bit or 64-bit came with a hard coded restriction to just 64 virtual machines concurrently. On the x86 platform the limit made more sense since the maximum possible virtual address space is just 4 gigabytes. This is also the main reason why the limitation survived into Virtual Server R2 SP1 in conjunction with 32-bit Windows operating systems. But as on 64-bit Windows, the sky's the limit, when it comes to virtual address space, well maybe not the sky and just 16 terabytes, users will be able to run no less than 512 virtual machines in a single Virtual Server R2 SP1. That's just as many instances of operating systems.

"Virtual Server 2005 R2 running on Windows Server 2003 64-bit (x64 editions). Virtual Server R2 running on Windows Server 2003 x64 Editions has a hard coded limit of running 64 virtual machines concurrently. Because x64 is becoming more common, we've had numerous customers (like our own Microsoft IT) hit the 64 virtual machine limit (with ample CPU, memory and storage resources to spare) and have requested we up this limit when running Virtual Server on Windows Server 2003 x64 Editions. We listened to our customers and did exactly that," Woolsey added.