Top 10 Server Virtualisation Benefits for Businesses

Could Virtual Servers Make Your Business More Efficient and Resilient?

Many businesses still rely on physical servers to run important applications, store files, manage users and support everyday operations.

Traditionally, each service may have required its own physical server.

A business might have one server for files, another for its accounts software, another for Active Directory and a separate machine for a specialist business application.

The problem is that these servers may use only a small amount of their available processing power and memory. They still consume electricity, occupy space and require individual maintenance, even when much of their capacity remains unused.

Server virtualisation allows several separate virtual servers to operate on one physical server.

This can help a business reduce hardware requirements, make better use of its technology and improve the way systems are maintained, backed up and recovered.

Microsoft describes virtualisation through Hyper-V as a way to maximise hardware utilisation, streamline IT operations and improve business continuity.

However, virtualisation must be properly planned.

Placing several important systems onto one physical host can create a larger point of failure unless suitable backups, monitoring, spare capacity and recovery arrangements are also introduced.

What is server virtualisation?

Server virtualisation uses software known as a hypervisor to divide a physical server into several independent virtual machines.

Each virtual machine behaves like a separate server.

It can have its own:

• Operating system
• Processor allocation
• Memory
• Storage
• Network connection
• Applications
• Security policies
• Administrator access

The physical server is normally called the host.

The virtual servers running on it may be called:

• Virtual machines
• VMs
• Guest servers
• Virtual servers

Although the virtual machines share the host’s physical hardware, they remain logically separated from one another.

For example, a business could operate:

• A virtual domain controller
• A virtual file server
• A virtual application server
• A virtual database server
• A virtual management server

All five systems could run on fewer physical servers than would traditionally have been required.

Microsoft Hyper-V virtualises processor, memory and input/output resources so multiple isolated virtual machines can share the same underlying hardware.

Does virtualisation mean moving everything to the cloud?

No.

Server virtualisation and cloud computing are related, but they are not the same thing.

A virtual server can operate:

• On a physical server inside your office
• In a private data centre
• At an IT provider’s data centre
• Within a public cloud platform
• Across a hybrid combination of on-premises and cloud systems

Virtualisation changes how the server uses hardware.

Cloud computing changes where and how computing resources are provided, accessed and charged.

A business may therefore virtualise its existing on-premises servers without moving its applications or information into a public cloud service.

It may also use virtualisation as the first stage of a future cloud or hybrid-cloud strategy.

Benefit 1: Reduce the number of physical servers

One of the main benefits of virtualisation is server consolidation.

Instead of purchasing a separate physical server for every application, several virtual machines can share a suitable host.

This can reduce the number of physical servers the business needs to purchase, maintain and replace.

For example, a company using five lightly utilised physical servers may be able to consolidate some or all of those workloads onto a smaller number of well-specified virtualisation hosts.

Microsoft notes that consolidating workloads through virtualisation can improve hardware utilisation, energy efficiency and reduce operational and maintenance costs.

The actual saving will depend on factors such as:

• Application requirements
• Server licensing
• Processor and memory usage
• Storage performance
• Availability requirements
• Expected business growth
• Backup and recovery needs

Consolidation should not mean placing every business system onto one underpowered physical server simply to reduce costs.

The host must have enough capacity to operate all its virtual machines reliably, including during periods of high demand.

Benefit 2: Make better use of server hardware

A physical server may contain powerful processors, large amounts of memory and fast storage.

When it runs only one lightly used application, much of that capacity may remain unused.

Virtualisation allows several workloads to share the host’s available resources.

One virtual machine may require more processing power, while another may mainly require memory or storage.

The hypervisor manages these resources across the virtual environment.

Hyper-V allows administrators to allocate and control processor resources using limits, reserves and weights so important workloads can receive appropriate capacity.

This can help businesses receive more value from their server investment.

However, resources must still be monitored.

Allocating more virtual processors and memory than the physical host can reliably provide may lead to slow performance and instability.

The environment should be designed around measured application requirements rather than assumptions.

Benefit 3: Reduce energy use and physical space

Every physical server requires:

• Electricity
• Cooling
• Network connections
• Rack or cabinet space
• Power protection
• Hardware maintenance

Reducing the number of physical servers can reduce some of these requirements.

This may be particularly valuable for businesses operating a server room inside their office.

A smaller physical environment may result in:

• Lower electricity use
• Less heat
• Reduced cooling requirements
• Fewer power sockets
• Less network cabling
• More available cabinet space
• Fewer physical components that can fail

Virtualisation does not remove the need for suitable environmental protection.

The remaining hosts may become more important because they run several business systems.

They should therefore be protected with:

• Suitable cooling
• Uninterruptible power supplies
• Hardware monitoring
• Redundant power where appropriate
• Reliable storage
• Appropriate warranties
• Tested recovery arrangements

Consolidation can improve efficiency, but it also increases the importance of the hardware that remains.

Benefit 4: Deploy new servers more quickly

Installing a new physical server can involve:

• Selecting suitable hardware.
• Waiting for delivery.
• Installing it in the server cabinet.
• Connecting power and networking.
• Configuring storage.
• Installing the operating system.
• Applying updates.
• Installing business applications.
• Configuring backups and monitoring.

A virtual server can often be created more quickly because the underlying hardware and virtualisation platform already exist.

The administrator can define the required:

• Processor allocation
• Memory
• Virtual hard disks
• Network connection
• Operating system
• Security settings

Templates and automation can also help ensure new virtual machines are built consistently.

Microsoft supports creating Hyper-V virtual machines through both graphical management tools and PowerShell automation.

This can be useful when a business needs:

• A new application server
• A test environment
• A temporary project system
• An additional domain controller
• A replacement for an ageing physical server

The virtual server will still require proper licensing, updates, security, backup and documentation.

Creating a virtual machine quickly should not mean bypassing normal IT controls.

Benefit 5: Scale resources more easily

Business requirements change.

An application may begin with a small number of users and later require more processing power, memory or storage.

Increasing the capacity of a physical server may involve:

• Ordering hardware
• Opening the server
• Installing components
• Scheduling downtime
• Confirming compatibility

A virtual environment can provide greater flexibility.

Depending on the platform and configuration, an administrator may be able to increase a virtual machine’s:

• Processor allocation
• Memory
• Storage capacity
• Network capability

The physical host must still have enough available resources.

Virtualisation cannot create unlimited capacity from insufficient hardware.

However, it can make the available capacity easier to distribute according to changing business requirements.

Resource monitoring can also help identify whether an application genuinely needs more capacity or whether its performance problem has another cause.

Hyper-V provides resource-metering capabilities that can report virtual machine processor, memory, network and disk usage.

This allows future upgrades to be based on evidence rather than guesswork.

Benefit 6: Improve server availability

Virtualisation can support high-availability designs.

A business may operate more than one physical virtualisation host as part of a cluster.

If one host fails, affected virtual machines may be restarted on another available host.

Microsoft Failover Clustering allows several independent servers, known as nodes, to work together to improve the availability and scalability of applications and services.

For Hyper-V environments, failover clustering can provide local high availability for virtual machines. When a host node fails, the cluster can restart affected virtual machines on another node that can access their storage.

This can reduce the impact of a physical server failure.

However, high availability does not mean there will never be an interruption.

The virtual machine may still need time to restart on the remaining host.

Applications and employees may experience a temporary loss of service.

A proper design must also consider:

• Shared or replicated storage
• redundancy
• Host capacity
• Power resilience
• Cluster configuration
• Application dependencies
• Monitoring
• Testing

If the remaining host does not have enough resources to operate the failed server’s virtual machines, the cluster may not provide the expected protection.

Benefit 7: Complete maintenance with less disruption

Physical servers require maintenance.

This may include:

• Installing firmware
• Replacing components
• Applying host updates
• Upgrading memory
• Changing network hardware
• Replacing the server

Without virtualisation, an application may be tied directly to that physical machine.

Maintaining or replacing it could require the application to remain unavailable.

Virtualisation can provide more flexibility because the workload is contained inside a virtual machine rather than being permanently tied to one physical server.

Hyper-V live migration can move a running virtual machine from one host to another with little or no noticeable downtime when the environment is properly configured.

An IT team could move virtual machines away from a host before:

• Installing updates
• Replacing hardware
• Completing planned maintenance
• Decommissioning the server

This can allow maintenance to take place without shutting down every application running in the virtual environment.

Live migration still requires suitable infrastructure, permissions, networking and host capacity.

It should be tested before it is relied upon during an important maintenance window.

Benefit 8: Simplify backup and recovery

Virtualisation can make it easier to protect an entire server as a single workload.

A virtual machine normally consists of configuration information and virtual disk files.

Suitable backup software can protect the VM from the host level rather than requiring every file to be handled individually.

Microsoft’s virtual machine backup tools can support VM-level, file-level and application-level recovery, depending on how the backup has been designed.

This may allow the IT team to restore:

• An entire virtual server
• Individual files
• Application information
• A virtual machine onto alternative hardware
• A copy of the server into a recovery environment

Virtual machines can also be replicated to another host, site or cloud environment as part of a disaster recovery strategy.

Azure Site Recovery, for example, supports disaster recovery for on-premises virtual workloads and Azure virtual machines.

However, virtualisation is not a replacement for backup.

A damaged, deleted or encrypted virtual machine may still be unusable.

Replication may also copy unwanted changes or corruption into the secondary environment.

The business still needs:

• Independent backups
• Suitable retention periods
• Protected or immutable recovery copies
• Separate backup credentials
• Recovery monitoring
• Regular restoration tests

A virtual machine that is easy to move is not automatically protected from ransomware, accidental deletion or administrator mistakes.

Benefit 9: Create safer testing environments

Businesses sometimes need to test:

• Software updates
• New applications
• Configuration changes
• Database upgrades
• Security policies
• Integration changes

Testing directly on the live production server can create unnecessary risk.

A virtual environment can make it easier to create a separate test server that resembles the production system without purchasing another physical machine.

The test system can be isolated from live users and information.

This allows the IT team to investigate whether a change may affect:

• Application performance
• Compatibility
• Security
• Network communication
• Other business systems

Hyper-V checkpoints can capture the state of a virtual machine before a planned change and allow it to be returned to that earlier state in appropriate circumstances.

However, checkpoints must be used carefully.

They are not a permanent replacement for backup.

Microsoft warns that checkpoints are stored with the virtual machine and can be lost if the underlying host or storage fails. Restoring a checkpoint can also return data to an earlier state.

For databases and other transactional applications, the correct testing, checkpoint and backup method should be agreed before changes are made.

Benefit 10: Support future cloud and hybrid working

Virtualisation can make it easier to move workloads between physical locations and different types of infrastructure.

Because the operating system and applications are contained within a virtual machine, the workload is less closely tied to one specific server.

This can support future projects such as:

• Moving servers to a data centre
• Creating a secondary recovery site
• Replicating workloads into Microsoft Azure
• Introducing hybrid-cloud management
• Replacing physical hosts
• Consolidating systems after an acquisition
• Moving selected applications away from the office

Hyper-V integrates with clustering, multiple storage options, Windows management platforms and Azure services for hybrid-cloud scenarios.

This does not mean every virtual server can be moved directly into the cloud without planning.

The business must still consider:

• Application compatibility
• Data location
• Internet connectivity
• Licensing
• Performance
• Security
• Ongoing cloud costs
• Backup and recovery
• Dependencies on local equipment

Virtualisation can provide flexibility, but the correct hosting location should be selected according to the application and the needs of the business.

A bonus benefit: Separate different applications

Running several applications directly on one operating system can create conflicts.

One application may require:

• A particular version of Windows
• Specific database software
• Different security settings
• An older application component
• A separate maintenance schedule

Virtualisation allows applications to operate in separate virtual machines.

This can reduce the likelihood that an update or configuration change for one system will affect another.

For example, a business could separate its:

• Domain services
• File storage
• Accounts application
• Database
• Remote access platform

Each virtual machine can then be maintained and protected according to its own requirements.

This separation can improve management and troubleshooting.

However, virtual isolation should not be confused with complete security isolation.

Virtual machines may still communicate across the network and may still share host, storage and management infrastructure.

Firewalls, permissions, security updates and network segmentation remain important.

Can virtualisation improve security?

Virtualisation can support security by separating workloads and applying controls to individual virtual machines.

Modern virtualisation platforms may support features such as:

• Secure Boot
• Virtual trusted platform modules
• Encrypted virtual disks
• Protected migration traffic
• Restricted management access
• Isolated virtual networks

Microsoft shielded virtual machines can use virtual TPM, BitLocker encryption and approved hosts to provide additional protection for suitable workloads.

However, virtualisation also creates important security responsibilities.

If an attacker compromises the virtualisation management platform, they may gain access to several important servers.

The environment should therefore use:

• Separate administrator accounts
• Multifactor authentication
• Restricted management access
• Prompt security updates
• Network segregation
• Security monitoring
• Secure backups
• Documented permissions

The hypervisor and its management tools should be treated as critical business systems.

Is server virtualisation cheaper?

Virtualisation can reduce some costs, particularly where several lightly used physical servers can be consolidated.

Potential savings may include:

• Fewer physical servers
• Reduced electricity
• Lower cooling requirements
• Less rack space
• Fewer hardware warranties
• Simplified server replacement
• Reduced maintenance time

However, virtualisation still has costs.

These may include:

• Powerful host hardware
• Storage
• Windows Server or virtualisation licensing
• Backup software
• Management tools
• High-availability infrastructure
• Implementation
• Monitoring
• Support

A resilient virtual environment with two hosts, shared storage and suitable backups may cost more than one basic physical server.

It also provides a different level of resilience and flexibility.

The correct comparison should therefore consider the complete business outcome rather than only the purchase price of the hardware.

Does virtualisation remove the need for physical servers?

No.

Virtual machines still require physical hardware somewhere.

Even cloud virtual machines ultimately run on physical infrastructure operated by the cloud provider.

For an on-premises environment, the business still needs suitable hosts, storage and networking.

The benefit is that applications are no longer permanently tied to one physical server.

This makes the workloads easier to manage, move, protect and recover.

What are the risks of server virtualisation?

Virtualisation offers many benefits, but poor implementation can create serious risks.

One host may affect several systems

If several virtual machines operate on one host and that host fails, multiple services may become unavailable at the same time.

This risk can be reduced through clustering, replication, suitable warranties and recovery planning.

Resource shortages

One virtual machine may consume too much processor, memory or storage performance and affect other workloads.

Capacity should be monitored and controlled.

Increased management importance

The virtualisation platform becomes a critical system.

Administrator access must be strongly protected.

Backup assumptions

Checkpoints and replication are sometimes mistaken for backups.

Independent, tested backups are still required.

Licensing complexity

Server operating systems, applications and management platforms may have licensing rules that change when workloads are virtualised.

Licensing should be reviewed before deployment.

Unsupported applications

Some application suppliers may have specific requirements for virtual environments.

Vendor support should be checked before migrating an important workload.

Poor documentation

A virtual environment can become difficult to manage when nobody records which virtual machines exist, what they do or how their resources are allocated.

Virtualisation should be supported by accurate documentation and regular reviews.

Should every business virtualise its servers?

Not necessarily.

Virtualisation may be particularly beneficial when a business:

• Operates several physical servers
• Has underused server hardware
• Needs better disaster recovery
• Wants to reduce downtime during maintenance
• Expects systems to grow
• Runs applications with different requirements
• Plans to move workloads to a data centre or cloud
• Needs a test environment
• Wants to improve hardware replacement

A dedicated physical server may still be appropriate when:

• An application requires direct access to specialist hardware
• The supplier does not support virtualisation
• The workload has unusually high performance requirements
• The business has only one very small server requirement
• Licensing makes virtualisation uneconomical
• The system controls specialist operational equipment

The decision should be based on business requirements rather than assuming that every server must be virtual.

What should be reviewed before virtualising?

Before migrating a physical server, the business should assess:

• Processor usage
• Memory usage
• Storage capacity
• Storage performance
• Network requirements
• Application compatibility
• Operating-system support
• Licensing
• Backup requirements
• Recovery objectives
• Security
• Supplier support
• Expected growth

The IT provider should also identify dependencies.

For example, a business application may rely on:

• A database on another server
• A licence server
• A specific IP address
• Specialist USB hardware
• A local printer
• An external supplier connection

These dependencies should be understood before the server is moved.

How can Hamilton Group help?

At Hamilton Group, we help businesses review, design and manage virtual server environments.

We can assist with:

• Server virtualisation reviews
• Microsoft Hyper-V
• Physical-to-virtual server migrations
• Windows Server upgrades
• Virtual machine management
• Host and storage design
• Failover clustering
• Server replication
• Cloud and hybrid-cloud planning
• Microsoft Azure
• Backup and disaster recovery
• Virtual server monitoring
• Security and access controls
• Hardware lifecycle planning
• Server licensing reviews
• Ongoing managed IT support

We can review your existing physical servers and help answer important questions such as:

• Are we making good use of our current hardware?
• Could several servers be consolidated?
• What happens if our main server fails?
• Can our applications run in a virtual environment?
• How quickly could a virtual server be restored?
• Do we have enough capacity for future growth?
• Are our backups independent and tested?
• Would clustering or replication reduce downtime?
• Should selected systems remain on-premises or move to the cloud?

Server virtualisation can reduce hardware requirements and improve flexibility, but the greatest benefits come from a properly designed and managed environment.

Contact Hamilton Group to discuss whether virtualisation could improve the reliability, efficiency and resilience of your business systems.

Call us on tel:0330 043 0069 or book an appointment with one of our experts.