The motivations are strong and compelling when making the choice to move towards virtualization as the solution for your data center.

Some of the factors include:

• Lower energy costs
• Greatly reduced data center physical footprint.
• More efficient use of hardware resources
• High availability
• Business continuity / easier disaster recovery
• Lower admin to server ratio

Before the migration is to move forward a detailed audit of current equipment, platforms, applications, etc must take place. All computing resources must be properly documented and enumerated. All backups need to be made current. If hardware is going to be re-tasked and used in the new virtualization schema, thorough testing needs to be done to assure full functionality and reliability.

Thorough preparation in the form diagramming, establishing documented process flows, and devising effective storage strategies is directly relational to the effectiveness and efficiency of your virtual migration and the resultant infrastructure. The planning stage is a good time to implement new ideas that will assist in ease of administration and further data center expansion. As with any IT infrastructure the complexity scales with data center size. Depending on the size of the data center, the virtual migration can be rolled out in phases to ease the transition and deal with issues on a smaller scale than would be necessary if the entire data center was migrated at once.

When the time comes to convert or migrate from purpose-built hardware servers to virtual machines, there are several options to consider. If the data center is small or your company can afford a small window of downtime, you can take servers out of production and then migrate to virtual machines. Although this procedure is more hands-on, it allows you to deal with issues out of band without affecting data integrity. For the larger data centers or data centers that cannot afford a maintenance window for migration (which is most likely the scenario), live migrations can be performed using one of many vendor-supplied tools that are readily available to automate the migration process, live, from bare metal server to virtual machine.

Once the decision has been made to take advantage of virtualization in your data center, the key to successfully accomplishing your objectives is research, and planning. The outcome and success of your virtualized environments will likely dictated by the level of preparation and detail you have provided in your project manifest.

Virtualization technology has made great strides in allowing the creation of the next generation of efficient, easily manageable, highly available, and dynamic data centers. Future developments in virtualization as a technology, the processes involved and hardware technology employed will be impressive and ground-breaking.

Desktop virtualization is a very hot topic these days as companies try to get even more efficient and consolidate resources, make better use of IT administrative hours and deploy desktops based on the needs of individual department tasks and computing requirements. Virtual desktops can be maintained centrally and are versatile when it comes to the end user access. The same virtual desktop used within the building can be accessed remotely.

Virtualization will be explored as an option in areas previously not considered feasible. Cell phone companies are already investigating its applicability in providing multiple phone environments on the same hardware. In the future you could choose your handset and then specify whether you wanted blackberry OS, Windows Mobile, or both.

A different mindset will have to be embraced to fully make use of the benefits inherent in virtualization. Steps normally applied to the flow of a project will either be shortened or removed all together. The use of virtualization will continue to spur increased ingenuity as the path from concept to testing, to production, is greatly shortened when virtual environments can be rolled out within minutes. When you remove the step of having to acquire physical computing assets before you can test your ideas, you take a great chunk of time and budgetary needs out of the equation towards the quest for a refined business solution.

Hardware technology will better enable the use of virtualization as components and will be designed to better facilitate the virtualization process, hypervisor, and interaction of data I/O between the software and physical layers. Advancements are already being made in these areas that will revolutionize the way data is accessed and manipulated. In the future I can see servers being purchased with the hypervisor already included in firmware, which will then be easily updated and managed with an even smaller foot print.

The future of virtualization means a refinement in the way people interact with technology and above all, better efficiency on all levels.

To maintain optimal uptime, high availability, and business continuity a comprehensive and up to date disaster recovery plan must be in place and meticulously documented. Disasters can be caused by power outages, human error, and certainly natural disasters. Server or data center downtime can cost the company dearly  whether it be monetary or a negative impact on reputation. Disaster recovery plans must also be tested thoroughly from time to time to make sure they are effective and meet recovery time constraints. In a data center that does not use virtualization this becomes a costly investment. A testing environment must be set up utilizing similar hardware to emulate what is already in place for an accurate test and analysis.

One of the many benefits of virtualization is the ease in which disaster recovery plans can be created and tested. When testing disaster recovery for virtual machines you eliminate the necessity of similar hardware as the VM’s are hardware independent. You can test your recovery plan using machines that have been taken out of production as long as they have the same hypervisor or virtual machine monitor on them.

Furthermore, the need to install the OS and all of the related applications to bring a machine back up is eliminated as virtual machines are just a collection of files that can easily be backed up in their entirety by copying them off (or backing them up) to another location. To restart the backed up virtual machine just copy it over to an operational server and start it up. This greatly reduces the time required for recovery.

If your entire data center has been brought down due to any nature of disaster the high portability of virtual machines allows you to transfer them to an alternate data center that is out of the affected area and restart. Your entire data center can be restarted at an alternate location using virtualization.

To further enhance and shorten the disaster recovery timeframe there are tools available that can facilitate the process by automatically transferring and restarting your virtual infrastructure at a predefined location. These tools are capable of advanced features such as the ability to start virtual machines in a pre-defined order so that any dependencies are resolved before the virtual machines that rely on them are started. A good example would be a virtual machine that ran an application which required a database to be running before it could start.        

Utilizing virtualization in your data center or server room assists you in overcoming some of the most trying and difficult tasks you may ever have to face. Due to the simple concept of virtualization separating hardware and the guest OS or virtual machine many tedious processes can become much simpler through automation and proper planning.

In keeping with the purpose of using virtualization technology the data storage solution must also be resilient and dynamic. Options in tasking and deploying storage for a virtual machine must follow suit with the core technology. Your choice for data storage needs to have high availability and fault tolerance for optimal uptime. Access to the data needs to be fast so as not to affect the performance of the virtual machine. Optimally, the data storage should be easily expandable without creating additional volumes.

The storage technology used and its method of access typically determines if all or parts of the objectives are met and if so, to what degree.

The practice of data storage on the same hardware as the virtual machine is strictly taboo as it defeats the purpose of deploying virtualization in the first place. Virtualization data storage is usually accomplished with Network Attached Storage (NAS) or a Storage Area Network (SAN). Both forms of storage have their benefits and drawbacks as will be explained later in this article.

A NAS – or Network Attached Storage comes in the form of a hardware device that usually contains one or more arrays of hard disks handled by one or more controllers. The advantage of having multiple controllers is that in the case one fails the other may take over the failed controllers RAID array, often in a somewhat performance deprecated state but none the less still operational. NAS devices come with an operating system that is meant to control the storage functions needed and provide device setup and management access in the form of secure shell access or VIA a web browser.  NAS uses common file based protocols to allow access to storage with NFS being popular for UNIX systems and CIFS for windows systems.

A SAN – or Storage Area Network is a high speed network of interconnected data storage devices. The storage devices connected can be of different brands. SAN’s are commonly used in somewhat larger storage implementations than NAS due to their cost and complexity, although they can encompass NAS devices. The drawbacks of using a SAN as compared to NAS are cost, and more complex administration.

Another difference between the two storage options is that with NAS you use file level operations and SAN’s uses Block level I/O.

Using network storage for your virtual machines there is always the concern of latency. This problem is being overcome with the use of TOE (TCP Offload Engine) enabled network cards and faster fiber channel and copper interconnects.

Your choice of virtual machine data storage ultimately should depend on the size and demands of your virtualization deployment scenario and of course budget.

To properly plan for any migration to virtualization, or virtual infrastructure startup, proper capacity and resource planning is paramount. The hardware upon which the virtual platform is to be installed must exceed the processing power, memory capacity, and disk I/O required for the virtual machines as tasked.  Although the ability to dynamically allocate most resources “on the fly” is a benefit of virtualization, a proper measurement for peak usage must be established. Once this is established the need for additional headroom past this point has to be added to hardware requirements thus allowing for future increased demand. Some might say that if the time comes when present hardware resources are no longer able to sustain the workload of the virtual machine(s) new hardware should be purchased to either:

1.     Create similarly tasked virtual machines to share the load.

2.     Migrate the existing virtual machines over to.

Arguments can be made for either scenario but this impasse should never be reached due to poor planning as the negative economic and production impact could result in repercussions that affect business continuity or sustainability.

The problem with industry standard server benchmarking tools is that they don’t provide the information necessary for virtual machines tasked with a single application or consider the virtual machine capacity of the host machines hardware. Virtualization benchmarking applications need to be specifically written for these tasks and need to be cross platform (accommodate various hypervisors and hosts) capable.

The Standard Performance Evaluation corporation (SPEC) has recognized the need for standardized virtualization benchmarking in establishing the SPEC Virtualization Committee with the following goals:

 ·      Delivering a benchmark that will model server consolidation of commonly virtualized systems such as mail servers, database servers, application servers, web servers, and file servers.
·      Providing a means to fairly compare server performance while running a number of virtual machines (VMs).
·      Producing a benchmark designed to scale across a wide range of systems.
·      Supporting hardware virtualization, operating system virtualization, and hardware partitioning schemes for server consolidation scenarios.

To this date a benchmark has not been developed by the committee. However, one of its members (VMware) has.

 

VMware VMmark is a freely available benchmark that was created with the goal of “open standards & platform neutrality”. VMmark is designed to deliver accurate performance valuations using testing methods that allow for real word benchmarks of virtual machines tasked with running specific applications common in the industry. Some of the typical workloads evaluated are virtual machines tasked as web servers, database servers, and java servers.  VMmark can properly evaluate server capacity by using a “tile based implementation” to benchmark a group of virtual machines tasked for various purposes as would commonly be present in the typical data center.  Results of the benchmarks can tell with reasonable certainty the capacity (in number of virtual machines) of a particular hardware platform as configured.

The virtual infrastructure is capable of being very dynamic in resource allocation by shifting resources where and when they are needed. Although the hypervisor provides these functions, many resources are finite due to the hardware configuration of the host machine. To plan a virtualization strategy we need to draw from benchmarks that can accurately gauge the capability and capacity of hardware to maintain mission critical applications in the data center. 

 In a bare metal virtualization solution you are running the Hypervisor on a very sparse Linux install (the majority) or other OS that contains just enough of the core to allow your Hypervisor to run and interact with hardware resources in order to provide the management functions necessary to build, deploy, manage, and interact with your Virtual Machines. The underlying OS is usually part of the install package for your bare metal virtualization platform

 The host model of virtualization requires a full install of a host OS on which the Hypervisor is then installed. The host OS may still run applications and function normally while basically running the Hypervisor as an application albeit a self contained one.

The benefits of using a Bare Metal implementation are numerous as the smaller footprint of the underlying OS uses considerably less system resources thereby granting the Hypervisor and its Virtual Machines access to more CPU cycles, available memory and storage space on the hardware platform. Factors that will weigh heavily on whether or not you can use bare metal virtualization are the hardware (server) that you have tasked or plan to purchase and the particular virtualization product you want to implement. If your server is not on the hardware compatibility list (HCL), which varies from vendor to vendor, then your best bet is to choose a hosted virtualization product. Overcoming driver issues is an advanced task and not one that you would choose to spend a majority of your time while trying to get your solution in production. In Bare Metal virtualization implementations you must also be comfortable accomplishing tasks via command line in a limited Linux shell. Some tasks are not available via the included web consoles such as transferring install packages/files and configuring storage arrays and connections.

If the hosted model is used you have the benefit of choosing a solution that will install on an operating system that you are comfortable with and not have the additional issues of hardware compatibility issues with your hardware as the Hypervisor will get its necessary packages from the underlying OS to simulate the hardware layer that is presented to the virtual machines you create. Of course the major drawback here is the host operating system can and will consume a larger amount of the hardware resources versus the bare metal solution.

I have covered the basics here but the choice of a virtualization implementation ultimately depends on the equipment you have at hand or are going to purchase, the goals of your implementation, and the skill sets of those doing the deployment.

Can you think of different scenarios that would warrant a bare metal or a hosted model virtualization deployment?

When you take into consideration the number of assets in the form of server hardware the average businesses data center has in place, factor in total cost of ownership and then measure this against the efficiency achieved by said assets in completing the tasks they were deployed for, you get a real good sense of true value. Value is achieved by maximizing output and utilization of each and every server plus reducing administration time and increasing uptime. 

The datacenter model of dedicated servers per function such as separate database, exchange (or email), domain controllers, and application servers is not efficient when compared to the alternative of virtualization. The reasons for the lack of efficiency are reduced server utilization, increased recovery time should a failure occur, and longer time to production on server rollouts to name just a few. All of these reasons also contribute to increased man hours to perform administrative tasks.

When it comes time to layout expenditures for new datacenter equipment it is often difficult for the project manager to convince those holding the purse strings that an initial higher investment in “big iron” (Larger, more powerful servers) with virtualization software will give more value to the corporation in the long run than several smaller outlays for purpose tasked servers as needs arise. This is a textbook case of perceived value being mistaken for actual value.  Should the big iron be purchased and a virtualization infrastructure be started, the need for another server will be satisfied by rolling out a virtual machine.

Instead of having 40 servers running at 30%-40% utilization you can have two or three “big iron” server with 40 virtual machines. As part of the virtualization infrastructure solution you will have these added benefits:

1. 1) Faster server provisioning
2. 2) Failover to another server should one server go down
3. 3) Optimization of server resources
4. 4) Higher utilization
5. 5) Lower electricity costs
6. 6) Reduced administration 

 

These all add up to increased value through efficient use of all resources and in the long run lower cost of ownership. 

An additional benefit is the ability to go with a leased model for server acquisitions as the virtual machines are not tied to the hardware.  So whenever the lease is up and new servers are acquired there will be no lengthy migration, just setup the new servers with your virtualization platform and move your virtual machines over to be restarted and placed into production.  Through the use of the virtualization model, actual value is realized from the start and will continue for many years.