RedHat KVM vs Vsphere vs Microsoft Hyper-V

Features	Red Hat Enterprise Virtualization for Servers	VMware vSphere 4.0	Microsoft Hyper-V 2008 R2
Bare metal hypervisor: A bare metal hypervisor is one that installs directly on the server hardware without requiring a full operating system. Red Hat Enterprise Virtualization leverages the modularity of Red Hat Enterprise Linux to provide hypervisor functionality without requiring a monolithic operating system to reside on.	Yes	Yes	Server Core and Hyper-V Server 2008 R2 installations are minimum 3 GB disk space.
Small footprint: The Red Hat Enterprise Virtualization hypervisor is <100MB, suitable for installation on local flash storage, boot from SAN, or PXE booting for diskless hosts.	Yes	Yes	No
Security: Only Red Hat Enterprise Virtualization leverages open source, enterprise-grade security developed in partnership with government agencies for high security. Red Hat Enterprise Virtualization uses the SELinux standard for security and is backed by Red Hat Network for security updates.	Yes	No	No
CPU virtualization: Red Hat Enterprise Virtualization-H is able to virtualize up to 256 logical CPUs (combination of cores and hyperthreading) on each host for resentation to virtual machines. Each VM can use up to 16 vCPUs for maximum efficiency.	Maximum 256 vCPUs per host. 256 logical CPUs per host. 16 vCPUs per VM.	Maximum 512 vCPUs per host. 64 logical CPUs per host. 8 vCPUs per VM	Maximum 64 vCPUs per host. 64 logical CPUsper host. 8 vCPUs per VM
Memory over commitment: Red Hat Enterprise Virtualization can allocate more virtual memory to its VMs than the host has physical memory.	Yes	Yes	No
Page sharing: Memory page sharing allows VMs with like operating systems to share physical memory to store redundant memory pages.	Yes	Yes	No
Processor hardware memory assist: Reduces the time required to exchange memory resources between the host and the virtual machine using the latest x86 processors.	Yes	Yes	No
Virtual NIC s: The hypervisor can present to each virtual machine multiple virtual network interface cards, each of which can map to different virtual networks and physical NICs on the host machine.	8 per guest	10 per guest	Max of 8 “internal” NICS for VM to VM traffic, 4 “external” NICS for connection to rest of Network
vLAN s: Support for virtual LANs on the virtual NICs inside the virtual infrastructure.	Yes	Yes	Requires Host OS and VM OS configuration
Network offload: Reduces CPU resources needed to process virtual networking and network IO by offloading to compatible NIC hardware.	Yes	Yes	Yes
Guest operating systems	Supports Windows 2003, 2008, XP, and Red Hat Enterprise Linux 3, 4, 5+	Support for most x86 operating systems, including Windows, Linux, UNIX	Windows 2003, 2008 (certain SPs only), Red Hat Enterprise Linux 5+ only
Intelligent failover: Red Hat Enterprise Virtualization high availability ensures that high priority virtual machines are automatically restarted on failure of the VM itself or the host on which it resides.	Yes	Requires Advanced or higher	Requires Windows Clustering
Maintenance mode: Red Hat Enterprise Virtualization hosts undergoing maintenance automatically have their guest VMs migrated to other available hosts and are removed as targets for migration until maintenance is complete.	Yes	Yes	No
Shared resource pools: Pools of resources such as CPU, memory, and storage are aggregated and managed at the datacenter or cluster level rather than machine-bymachine.	Yes	Yes	No
Cluster resource policies: Red Hat Enterprise Virtualization allows administrators to set cluster policies for resource smoothing.	Yes	Enterprise and Enterprise Plus only (DRS)	No
Shared storage: Red Hat Enterprise Virtualization can use NFS, iSCSI, and Fibre Channel shared storage for the storage of virtual machines.	Yes	Yes	Limited
VM snapshots: Red Hat Enterprise Virtualization virtual machine snapshots allow administrators to apply patches and upgrades in a transactional way and roll back to a known good snapshot if the patch runs into an issue.	Yes	Yes	Yes
Storage multipathing	Yes	Yes	Yes
Virtual disk files: Virtual disks are stored as disk files on the various storage domains.	Yes	Yes	Yes
Storage virtualization: Red Hat Enterprise Virtualization aggregates and distributes storage resources to maximize flexibility and utilization.	Yes	Yes	Yes
Application programming interface (API )	Yes	Yes	yes
Logging: Red Hat Enterprise Virtualization Manager provides extensive logging for troubleshooting and research.	Yes	Yes	Yes
PXE boot support: Red Hat Enterprise Virtualization Manager supports PXE boot for network installation of virtual machines.	Yes	Yes	Yes
Active directory integration: Red Hat Enterprise Virtualization Manager interfaces with your existing Microsoft Active Directory for user access and authentication.	Yes	Yes	Yes
Access control: Administrative and user access to your virtual datacenter can be controlled and managed from Red Hat Enterprise Virtualization Manager.	Yes	Yes	Yes
Remote console: Red Hat Enterprise Virtualization Manager allows console access to virtual machines using secure VNC or desktop optimized SPICE remote desktop technology.	Yes	Yes	Yes
System monitoring: System status can be monitored from Red Hat Enterprise Virtualization Manager.	Yes	Yes	Requires SCOM
Alerts and notifications: Red Hat Enterprise Virtualization Manager can report errors and warnings to administrators via email.	Yes	Yes	Yes
Central control and visibility: Red Hat Enterprise virtualization Manager is your single-view Management GUI for your entire enterprise virtualization infrastructure.	Yes	Yes	Requires multiple products to fully manage
Thin provisioning: Allows the creation of virtual machines with virtual disks that do not take up all of their allowed space upon creation. This allows better use of storage resources as needed.	Yes	Yes	Yes