Summary

Project Kensho OVF technology provides the Citrix ecosystem with excellent tools to create and consume virtual appliances based on the OVF standard.  Project Kensho OVF technology is currently available in two utilities: 

This article aims to describe basic use cases of each tool and where it fits within the greater context of deploying and consuming virtual appliances using the Open Virtualization Format (OVF).

Background

Project Kensho is a Citrix Labs endeavor tasked with de-risking and improving our understanding at applying DMTF OVF and CIM technology to XenServer. 

In the case of OVF, the standard is new and exciting. Its potential to reduce costs and improve virtual machine deployment for Citrix internal and external partners and customers is enormous.  Today, it is one of the most exciting technologies in the world of virtualization.

Project Kensho OVF technology is present in both the Project Kensho OVF Tool and XenConvert 2.0.1.  Each tool is unique in how it uses OVF and its position in the user community. 

In the simplest terms, the Project Kensho OVF Tool is aimed at OVF based virtual appliance creation and consumption where as XenConvert 2.0.1 is a P2V/V2V conversion utility supporting OVF virtual appliances.

Each offers the user different paths to create, convert and import OVF based virtual appliance content into XenServer.

Project Kensho OVF Tool

First released in October 2008 as an ongoing series of Tech Previews, the Project Kensho OVF Tool targets the creation and consumption of OVF based virtual appliances. This utility is part of the Project Kensho Tech Preview suite consisting of the Project Kensho OVF Tool and the Project Kensho XenServer CIM Interface. 

The Project Kensho OVF Tool is a full featured import/export utility offering users the latest OVF capabilities. The utility accommodates both the XenServer and Microsoft Hyper-V hypervisors and has the ability to directly import VMware OVF/VMDK content without conversion.

Unlike XenConvert, the Project Kensho OVF Tool is not targeted at static file format or physical to virtual conversion.  The utility requires the user to have administrative privilege to the hypervisor.  It interfaces directly with the hypervisor enumerating VM content for export and identifying hypervisor hosts for import.  The Project Kensho OVF Tool’s primary function is to manage movement of OVF packages into and out of the hypervisor.

Project Kensho OVF Tool – Appliance Creation (Export)

Virtual appliance producers have the ability to create virtual machine appliances by exporting one or more virtual machine guests as an OVF package from either the XenServer or Hyper-V host. 

OVF supports one or more virtual machines within a single package.  This enables virtual appliance producers with the ability to package entire datacenter suites into a single file.  This is very useful when distributing suites like XenApp or other multi-server products.  Currently, the Kensho OVF Tool is the only Citrix utility capable of exporting OVF content directly from a hypervisor.

When exporting the appliance, the user has the ability to embed an End User Licensing Agreement (EULA) into the OVF.  The EULA is presented during import forcing the consumer to agree or decline the terms of use of the appliance. 

For added security, the user can digitally sign the OVF file and encrypt the virtual disk content.  These features add additional value to the virtual appliance’s integrity.  Users can also compress and add a file manifest to OVF package.

Project Kensho OVF Tool – Appliance Consumption (Import)

Consumers of the OVF package have the option to import the virtual appliance into a XenServer or Hyper-V hypervisor.  Among other features, the Project Kensho OVF Tool enables this process with features such as hardware mapping and integrity validation of the OVF package.

Hardware mapping eases post virtual appliance import configuration steps.  For example, a user could map the network interface card (NIC) described in the OVF to the virtual networks unique to the target XenServer. The same support exists for storage and system mapping.

One highly useful feature is the direct import of VMware OVF/VMDK content into a XenServer or Microsoft Hyper-V environment.  This capability reduces time and costs as Project Kensho implements fix up capabilities making migration of the VMDK easier and less time consuming.

XenConvert 2.0.1

As the first mainstream XenServer utility to adopt OVF, XenConvert 2.0.1 applies Project Kensho OVF technology to the conversion process.  As a Physical to Virtual (P2V) and Virtual to Virtual (V2V) converter, XenConvert 2.0.1 now gives virtual appliance users a number of options to either create OVF content for import into XenServer or convert OVF content produced by 3rd party products like VMware. 

Unlike the Project Kensho OVF Tool, XenConvert 2.0.1 does not require administrative rights to a XenServer in order to convert physical or virtual machine assets into formats compatible with XenServer.  The utility can perform its conversion functions without any XenServer interaction.  However, in scenarios where the user chooses to import into XenServer as part of the conversion process, the utility conveniently offers this capability thus requiring the user to authenticate to a XenServer with administrative credentials.

In the P2V scenario, XenConvert 2.0.1 facilitates the creation of an OVF based virtual appliance by using a physical machine as the appliance reference.  This is a unique use case as the creator of the virtual appliance now has another avenue of flexibility in determining the source of the virtual appliance.

One helpful use case is converting an existing XenServer XVA virtual disk to an OVF/VHD package.  This gives virtual appliance users the option to easily convert the XVA to a standards based virtual appliance format.

Another use case is converting from a VMware OVF/VMDK to XenServer.  Kensho OVF technology allows XenConvert to convert and import VMware OVF content into a XenServer environment.  This is very helpful when moving between hypervisors and gives users the freedom of OVF interoperability at the virtual disk level.

There are many more possible use cases employing Project Kensho OVF technology found in XenConvert 2.0.1.  XenConvert 2.0.1 supports OVF packaging options like compression, digital signatures, encryption and archiving the OVF package as well as attaching EULA information to the virtual appliance.

For use cases where P2V and V2V conversion is a must, XenConvert is an excellent tool to convert and import OVF content into XenServer.  And, it represents yet another method of creating and consuming OVF based virtual appliances. 

Conclusion

Project Kensho OVF technology offers users a variety of options whether using the Project Kensho OVF Tool or XenConvert 2.0.1.  Each utility allows creators and consumers of OVF based virtual appliances a variety of paths into XenServer creating flexibility for all users of the technology. 

By providing tools to address the conversion of physical and virtual disk formats to XenServer as well as the import and export of OVF content, Citrix is actively positioning customers and partners for the move into the virtual appliance world.