Microsoft poured features into Windows Server 2008 R2 Hyper-V, but some IT managers already have ideas about what...
they'd like to see in an upcoming release of the hypervisor.
Some of the capabilities Microsoft added into Hyper-V R2 include Live Migration, Rapid Provisioning, third-party cluster file system and cluster volume manager support, improved network performance, virtual disk hot-add and MAC address security. But the company's biggest competitor, VMware Corp., still keeps its edge.
One major feature that is missing in Hyper-V R2 is the ability to assign a run priority to each virtual machine (VM) in a cluster for high availability. Leonard Niebo, director of IT for the Brick Township Board of Education in New Jersey, has two Hyper-V hosts running 13 to 14 VMs each with Windows Server 2008 and plans to upgrade to Hyper-V R2 this summer. He said VM run priority for high availability would be a great enhancement.
"I would like to be able to have a Hyper-V host with my must-have apps, and a separate host with secondary apps that aren't as important, and be able to prioritize which ones come back up first," Niebo said.
IT shops want memory overcommit
Another hole in Hyper-V is memory overcommit. Microsoft has stated that this feature is unnecessary because "users don't want to overcommit resources." But some IT managers beg to differ. For instance, Robert McShinsky, a senior systems engineer with Dartmouth-Hitchcock Medical Center (DHMC) in Lebanon, N.H., said he wants the memory overcommit capability because he experiences memory bottlenecks in Microsoft virtual server implementations from Virtual Server 2005 to Hyper-V R2, which he now uses.
DHMC runs Windows Server 2008, Windows Server 2003 and Red Hat Linux as guest operating systems with Hyper-V and has some virtualized Web servers, Microsoft Office SharePoint Server, medical applications, domain controllers, file and print servers, Citrix servers and more.
The medical center uses HP BL460c G5 servers with 64 GB of RAM. "The new servers we have now have 12 memory slots so we can go higher, but it can be quite costly to get into the 16 GB DIMMs," McShinsky said.
Memory overcommit would be helpful to maximize usage and reduce the cost of the host, he said.
Brick Township Board of Education's Niebo added that the memory overcommit feature would be useful because it would give him elasticity for the amount of memory per VM to provision. Chris Wolf, a virtualization analyst with Burton Group, based in Midvale, Utah, wrote the October report, Windows Server 2008 R2 Hyper-V, which took the position that Microsoft's stance on memory overcommit is misguided.
"Memory overcommit is analogous to the pagefile in the Windows OS," Wolf said. "It's hard to make a case that it isn't important for virtualization when the Windows OS has used memory paging to overcommit memory for Windows services and applications for more than a decade."
Plus, development, testing, training and many desktop virtualization scenarios benefit from the memory overcommit capability, and "Hyper-V's feasibility for virtual desktops would be far more practical if it had memory overcommit," he said.
Some new features can be better too
Users and analysts said there is also room for improvement in some of the new capabilities added to Hyper-V R2. For instance, Microsoft added Live Migration, but users can't simultaneously migrate two or more VMs.
McShinsky said he would also like to see Live Storage Migration work without downtime. "Hyper-V R2 with System Center Virtual Machine Manager 2008 R2 will allow for storage migration from one storage platform to another [LUN to LUN] with a small amount of downtime," he said. "VMware can do this without downtime. I work in a 24/7 hospital. The more that can be done without affecting uptime, the better."
Microsoft also added Clustered Shared Volumes (CSV) to support multiple VMs per LUN, but the feature is limited, McShinsky said. For instance, he would like to see "full access to volume from any node, Quality of Service options and Over Network Access to the volume. Give me something like VMFS or Melio FS."
McShinsky wants Microsoft to improve backup support for host-level VM backups. "Why do I have to use System Center Data Protection Manager 2010 beta to back up my production Hyper-V R2 environment with Clustered Shared Volumes?" he asked. "DPM 2010 is not scheduled to be released until late Q1 of 2010. So, at best, that will be five months after the release of Hyper-V R2 … [and] this late arrival seems to kill some of the momentum of the Hyper-V R2 release."
Plus, Niebo said System Center Virtual Machine Manager (SCVMM), which has improved since the first version of Hyper-V, could offer richer reporting capabilities. "The reporting is OK, but having used the VMware [management software], I have something to compare it to, and VMware's was more granular," he said.
To make up for what's missing in Hyper-V R2, customers can purchase third-party products or take extra time on tasks such as updating cluster-wide virtual switch configuration – and those expenses should be considered in Hyper-V cost comparisons, according to the Burton Group report.
Let us know what you think about the story; email Bridget Botelho, News Writer