New in Essentials for XenServer 5.5

• Extended Storage Integration:
  The native Storage Integration based on the StorageLink technology has new functions, such as Fast Cloning of virtual machines, and offers storage manufacturers further options for integrating their solutions. Numerous leading storage manufacturers have already signed up to the CitrixReady program. 
  
  
• Automated Stage Management:
  This feature optimizes and automates the processes which an application goes through in an virtualized environment throughout the entire lifecycle – from initial tests in the development environment to use on productive servers. The applications can be moved between different platforms via defined workflows with a few clicks of the mouse, e.g. from the test environment to the productive environment. Thanks to Multi-Hypervisor support, platform limits are neither here nor there.
  
  
• Dynamic Work Balancing:
  This feature extends the Live Motion function available on the cost-free XenServer platform to include the automated, directive-based movement of running VMs to another piece of physical hardware. If defined thresholds are reached, VMs are migrated onto other physical servers in the resource pool dynamically. This process is automated; there is no need for manual intervention on the part of the IT personnel.
  

Microsoft Hyper-V

Hyper-V is a Tier-1 Hypervisor, meaning that it is a narrow tier between the hardware and the virtual machines (VM, Microsoft: "Child Partition"). Alongside the VMs, there is a Parent Partition which is allowed to access the hardware directly and can pass this to the Child Partitions. The structure is shown in the Hyper-V Architecture (source: Microsoft). 

R2 will make it possible to perform a Live Migration of VMs. Here a virtual machine is moved between two Hyper-V Servers without interruption. A shared memory which can be accessed by both (or several) Servers is required. This memory can also be configured with several VMs from R2 onwards, and it can nevertheless be used in High Available (HA) mode.

The Microsoft Hyper-V Server 2008 R2 will be free of charge. It includes all the aforementioned features. The Parent Partition is a Windows 2008 Core which has been adapted specially for Hyper-V.

The standard Windows 2008 drivers can be used for accessing the hardware. HA and Live Migration are depicted by the familiar Windows 2008 Cluster functionality, which supports up to 16 Nodes. Microsoft supports Windows Version 2000 and later, SUSE Linux Enterprise Server 10/11, and RedHat RHEL (Red Hat Enterprise Linux) 5 as VMs.

For the management of several Hyper-V Hosts, Microsoft provides System Center Virtual Machine Manager (SCVMM). Further details can be found at http://www.microsoft.com/hyper-v-server/en/us/r2.aspx. 

VMware ESX

With its current Hypervisor ESX4 as part of the comprehensive vSphere 4 infrastructure solution, VMware offers a stable, high-performance, and flexible basis for the setup of virtual environments. Hypervisor supports virtual machines with up to 8 CPUs and 256GB RAM, which also allows the virtualization of resource-intensive applications such as database or ERP systems.

Managed by the vCenter, the central management application, all key tasks when dealing with virtual machines can be performed quickly and easily.

Additional features allow almost interruption-free operation of the virtual machines in the event of maintenance or errors, and they simplify patch and backup tasks. The features in detail:

• VMware High Availability (HA) 
  Automatic start-up of virtual machines after a hardware failure
• VMware VMotion / StorageVMotion
  Interruption-free movement of virtual machines during operation, both between ESX servers and between storage units
• VMware Fault Tolerance
  Maximum failure protection by creating a shadow instance of a virtual machine, which takes over productive operation from the primary VM automatically without interruption in the event of a fault
• VMware Distributed Resource Scheduling (DRS) 
  Optimum load distribution across all ESX servers with the aid of VMotion technology
• VMware Update Manager
  Integrated patch solution for the Hypervisor itself and virtual machines based on Windows or Linux
• VMware Consolidated Backup (VCB) and VMware Data Recovery (VDR) 
  Optimum backup of the virtual machines and their data
• VMware vShield Zones 
  Integrated firewall protection for the virtual machines

  

With these options, VMware offers a comprehensive solution for the virtualization of your IT infrastructure. This solution is rounded off by products for geographically distributed Disaster Recovery, Lifecycle Management, Lab Automation, and performance monitoring of the infrastructure up to transaction level within a virtual machine.

Countless products from third parties have already been adapted and approved for use and connection with the virtual infrastructure of VMware, meaning that a wide support basis has been established.