Virtualization 1.0 is yesterday’s news; the days of virtualization being used only as a tactical tool to drive consolidation and higher system utilization are quickly ending. For the most part, companies have figured out how to get improved utilization, and are using server virtualization in a wide range of usage models across development, testing and some rather interesting production/mission-critical scenarios. Its use is gradually maturing from simple partitioning and encapsulation to leveraging the mobility of virtual machines to improve management and operations of IT environments. This is allowing the change in deployment models for virtualization from typical scale-up approach (SMP with large Memory servers) to a scale-out model.
Virtualization 2.0 includes a host of new use cases (shouldn’t be surprising to anyone) that include:
· Load-balancing for SLA Mgt
· Power-optimization
· High availability (no downtimes)
· Disaster recovery and business continuity
· Hosted clients
· SOA & Utility computing.
I see three key foundational tenets as the underpinnings for these usages. First are the “abstraction” and the “convergence” of compute servers, storage and networks. It has been happening, but virtualization 2.0++ is driving (and will continue to drive) a seismic rethink in how Data centers are architected, and the data center would be a “Fungible” pool of infrastructural resources, for a wide variety of services that IT provides to run the businesses. I will get deep into the implications of this to IT operations, etc, in a follow on blog, but will leave you with this thought. The new control point in the data center, both architecturally and operationally, would be the integration of compute, storage and network virtualization architectures. Key industry players like IBM, HP, Cisco, EMC, VMWare and Microsoft are introducing integrated solution architectures targeted at positioning themselves as the first vendor of choice for this emerging direction. This foundational tenet, coupled with the merits of Service-Oriented Architectures (SOA), is providing an infrastructure for ‘Cloud Computing’.
The Second core tenet is the mobility of Virtual machines - The migrate-ability of the ‘encapsulated’ Virtual machines on this abstracted infrastructure for the best performance, operational cost and SLA management. They are no longer tied to a server or a set of servers. In some cases they are not tied to a datacenter; hybrid models are emerging where these VMs would execute in the ‘enterprise’ data center, or on external clouds – the optimal place for the best TCO, and SLA management (Yes, yes, there are security, compliance, accounting, performance concerns… I agree)
The third core aspect is Manageability. The abstraction and the mobility, coupled with IT’s job of ensuring security, reliability and compliance brings a totally new set of requirements for Manageability.
If done right, the benefits of Virtualization 2.0 (and 2.0++) to IT shops would be in the form of reduced administrative costs, improve productivity even as demand goes, reduce energy and cooling costs, etc, however, there are quite a few challenges with the adoption of Virtualization 2.0. Let us briefly look at these.
Challenges with Virtualization 2.0
1. There is a significant challenge in the management of large scale virtual infrastructures. There are no clear boundaries and responsibilities in terms network, storage and datacenter management teams. The emphasis on monitoring and management in Virtualization 2.0 is shifting from virtual machine (VM) management to service management; i.e., knowing how a business service is performing and which components of the Data Center (network, server, VM, applications) are working properly and which are not. Hence, it's no longer sufficient to just monitor the uptime or resource usage levels of virtual machines and physical servers and conclude that the entire IT infrastructure is working right. More granular monitoring and management of resources would be needed to provide precise QoS and SLA management.
2. VM Mobility – The Mobility of Virtual machines puts requirements on the underlying server CPU architectures, and has challenges with networks and storage. Such mobility occurs via either a cold migration - which simply copies the virtual machine and restarts a copy somewhere else. Or a live migration, which moves a live running virtual machine, while maintaining state. There are clear cases where cold migration is sufficient, but the flexibility and agility that is inherent with the virtualization 2.0 use-models requires the ‘live migration’ of VMs.
· VM Mobility and the ‘Compatible CPU Architecture’ requirements: Successful migration relies on compatibility between the processors of the host servers within a cluster. For live migration to take place, the source and destination servers must be in the same cluster and must have processors that expose the same instruction set., In the past, it has not been possible to mix servers based on different processor generations, each of which support different instruction sets, within the same cluster without sacrificing the ability to live migrate VMs across hosts supporting different instruction sets. As a result, IT organizations have needed to create separate clusters for different server generations. This has limited our ability to provide an agile data center environment because it creates islands of compute capacity, resulting in data center fragmentation. Intel’s VT FlexMigration assist, together with VMWare’s Enhanced VMotion, provide a solution. These products are designed to allow IT to maximize flexibility by creating a single pool of compute and memory resources using multiple generations of Intel processor-based servers within the same cluster. This can reduce the number of pools, increase the efficiency and utilization of servers.
· VM Mobility & networks: Today, when Virtual machines move on the virtual infrastructure, its network properties and policies are not retained. Connection state, ACL, Port Security properties, ACL Redirect, Qos Marking, etc are lost as these VMs move across hosts. Technologies like the VMWare distributed switch, and Cisco’s Nexus 1000v are specifically targeted to address the ‘Network and Security’ aspects of VM Mobility.
- Licensing in Virtual environments: Licensing rules for applications, development tools, data management tools and operating systems often make a completely virtual environment more costly than the organization expects. Most all ISVs are looking at ‘virtualization’ friendly licensing models, but they are far from being there. Example: With Oracle database servers, if you have a 16core server as your host, it doesn’t matter if you database VM uses 4 vCPUs, you would still need the license for 16 cores. If you would “Live Migrate” the VM, you would need the license on each of the host… This gets prohibitively expensive and impractical.
- 10G Networks and Converged Fabrics: The Compute power on the servers has increased dramatically, and with the advent of 8 core processors, the bottleneck clearly moves out of the server, and on to the network and storage bandwidths and throughput. Virtualization 2.0 will require the consolidation of network traffic and will also increase the need for more bandwidth to the server, both of which will be possible as enterprises make the move to converge and consolidate data, storage, and inter process traffic on 10GbE networks. 10GbE and the converged networks need new switches, access cards, and also a rethink of how applications view the network I/O.
- Security and Isolation guarantees – The hosting of multiple ‘services’ on an abstracted virtualized infrastructure has very specific needs on Security and isolation, multi-tenancy isolation, compliance and audit requirements.. In addition to providing these on a server (for a given service), the infrastructure has to guarantee these across the infrastructure – doesn’t matter on which server (and where) the service and data reside/execute, they need to be secure and isolated.
In conclusion, Virtualization 2.0 would have a dramatic impact on the architecture of the data center, and also IT architectures and operations. IT shops will use virtualization for administrative cost reduction, better resource allocation, and more flexibility in a mobile world. Coupled with Service Oriented Architectures,, the promise of true service-oriented/utility computing might be closer than it has ever been with Virtualization.
Would love to hear your thoughts and views on this..
