At the very least, the entrance of Microsoft and Hyper-V into a market in which Xen-based offerings are already giving VMware a run for its money means that the days of VMware as the no-brainer option for server consolidation and similar virtualization-based tasks are over.With its June 26 release of Hyper-V, Microsoft presented x86 server
virtualization leader VMware with what may prove its toughest challenge to
date.
That's because while Hyper-V trails VMware's ESX Server in core features,
management options and guest operating system support, Microsoft's new virtualization
offering boasts a pair of significantand familiaradvantages.
Hyper-V is bundled with Windows Server 2008, and carries no additional
charge. Microsoft will, however, sell you a version of Server 2008 sans
Hyper-V. The estimated MSRP of Windows Server 2008 Standard is $999. The same
server without Hyper-V is $971.
At the very least, the entrance of Microsoft and Hyper-V into a market in
which Xen-based offerings are already giving VMware a run for its money means
that the days of VMware as the "no-brainer" option for server
consolidation and similar virtualization-based tasks are over.
Based on eWEEK Labs' tests, Hyper-V is worthy of consideration as a
virtualization option at sites of all sizes, and particularly those already
running or planning on upgrading to Windows Server 2008. Hyper-V does require
server hardware powered by x86-64 processors with hardware virtualization
extensions, so companies that wish to use older x86 hardware as hosts for
virtualization must stick with ESX Server, or opt for Microsoft's
lower-performance Virtual Server product.
This first version of Hyper-V, which eWEEK Labs previously tested in beta
form, currently lacks some of the scalability offered by VMware's ESX Server.
For instance, Quick Migration, where a virtual machine is moved from one
physical host to another, is nowhere near as sophisticatednor as quickas the analogous
function in VMware.
However, based on Microsoft's track record for overcoming scalability
issues, as in Exchange Server and Active Directory, I expect that Microsoft
will manage to make up scalability ground as it revs through subsequent Hyper-V
versions.
Less clear is whether Microsoft will close the gap between Hyper-V and ESX
Server in the breadth
of guests that Hyper-V hosts effectively.
As matters now stand, Microsoft's support for operating systems beyond Windows
is characteristically poor. While pretty much any x86-based operating system
will run under Hyper-V, the so-called "enlightened" drivers required
for full performance are available for most Windows versions and for Novell's
SUSE Linux Enterprise Server.
Hyper-V in the lab
I installed Windows Server 2008 with Hyper-V on an HP ProLiant ML115 server
with an AMD Athlon dual-core 4450 B
processor. The server was equipped with 4GB of RAM
and a single 1GB NIC (network interface card). Hyper-V is treated in Windows
Server 2008 as a server role, but since the version of Hyper-V that shipped
with Server 2008 RTM was a beta, I had to download the
updated Hyper-V code from Microsoft's Web site.
I set about creating some virtual machines by firing up Microsoft's Hyper-V
Manager, with which I built four virtual machines: VM One ran Windows Server
2003 with service pack 1; Two and Three were W2K3SP2 (Windows Server 2003 with Service
Pack 2) and VM Four was Novell's SUSE Linux Enterprise Server 10 with SP2.
I also tried my hand at importing a few VMs that I'd created, but the fact
that I'd built those VMs using the beta version of Hyper-V frustrated those
import efforts.
As with VMware's ESX server, the first order of business after installing a
guest operating system is installing helper files to optimize guest performance
in the hypervisor environment. In the case of Hyper-V, Microsoft currently
supplies helper utilities called "integration services" (sometimes
referred to as "integration components") for a limited range of guest
operating systems. I was able to use the virtual integration services setup
disk on my W2K3SP2 virtual machines but was met with an "unsupported
operating system" error message when I attempted the same thing on my
Windows Server 2003 SP1 machine.
Hyper-V's management interface made it easy to adjust the attributes of my
VMs, including their assigned memory, processor type, IDE
controller type, network adapters and other hardware components. I also used
the interface to change the VM name, install integration services, and change
the snapshot file locations.
The Hyper-V Manager is quite simple to use and IT managers should have
little trouble training staff to use the system to create and maintain VMs. The
system provided me with useful error messages when I attempted illegal actions.
For example, I directed two VMs to use the DVD
drive at the same time. It was easy to manually remediate the problem, although
I'd like to see Microsoft automate remediation of device contention so that the
Hyper-V Manager handles physical device delegation based on requests without
manual configuration changes.
I found virtual networking simple to set up and easy to use in Hyper-V.
There are only three kinds of networks that can be created: external, internal
and private. I used external networks to enable my VMs to access the Internet
and internal networks so that the VMs could provide services on my local
network. Private networks are used to isolate traffic to VMs installed on a
physical host. I didn't try this type of network, but for workloads that must
be securely contained from the rest of the network it's a handy feature.
As in VMware's management environment, I was able to accomplish certain
configuration tasks while my VMs were turned on and running, such as installing
integration services. Other actions, such as modifying my network hardware,
required that I shut down my VMs.
The Hyper-V Manager sits at the core of a larger management portfolio that
includes the optional SCVMM (System Center Virtual Machine Manager) 2007, which
is suitable for controlling larger Hyper-V deployments. I'm looking forward to
the release of SCVMM 2008, which will add support for managing non-Microsoft
hypervisors as well, and should enable Microsoft shops to work around the guest
limitations of Hyper-V by bringing more cosmopolitan hypervisors into the mix.
During my tests, I was able to abuse one test server while other virtual
machines on the same physical host quietly processed away on their workloads.
My VMs ran with very little contention and did not interfere with each other.
In subsequent tests I'll be stressing CPU, disk and network I/O more rigorously
to see how Hyper-V handles the load.
Hyper-V, in conjunction with Windows Server 2008, provides for failover
clustering. The clusters can use SAS (serial-attached SCSI) or Fibre Channel to
network the clustered servers and mass storage devices. There are several
limitations on setting up failover clusters that have more to do with the
underlying Windows OS than Hyper-V. IT managers should carefully consider these
factors, such as the use of identical NICs and no parallel iSCSI, when making a
decision about using Hyper-V to construct a failover compute cluster.
eWEEK Labs Technical Director Cameron Sturdevant can
be reached at csturdevant@eweek.com,
or through his blog, here.
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