Virtualization refers to technologies designed to provide abstracted computing resources rather than direct access to actual physical hardware. There are several main types of virtualization used for different purposes.
Benefits of Virtualization
Virtualization offers many potential benefits:
Allows multiple operating systems and applications to run on the same server or PC hardware concurrently in isolated environments. This increases efficiency and utilization.
Enables workload mobility and portability with few dependencies on underlying hardware. Virtual machines can easily move between servers.
Disaster recovery and business continuity is easier using virtualization for rapid provisioning of duplicate servers.
Testing and development environments can make use of ready-made virtual machines and configurations rather than physical hardware.
Server and application consolidation onto centralized virtualized platforms allows better resource optimization.
Server virtualization refers to partitioning a physical server into multiple isolated virtual environments known as virtual or private servers. Each virtual server hosts an independent operating system and associated applications. The virtualization software layer abstracts the underlying hardware, meaning virtual servers share CPUs, memory, storage, and more regardless of precise physical hardware configuration.
Popular server virtualization platforms include VMware ESXi, Microsoft Hyper-V, Citrix XenServer, Red Hat Virtualization, and more. Enterprises usually deploy these to consolidate workloads from underutilized standalone servers into a centralized, easily managed virtual infrastructure with maximized hardware utilization.
Also referred to as virtual desktop infrastructure (VDI), desktop virtualization delivers a virtual machine-hosted desktop environment typically hosted on centralized servers to endpoints like PCs, laptops, tablets, and more over the network. It separates the desktop environment and associated apps and data from the client hardware, allowing users to access desktops from multiple devices.
Common VDI platforms include VMware Horizon, Citrix Virtual Apps and Desktops, Microsoft Remote Desktop Services, and Parallels RAS. Uses include provisioning standardized desktops, easier centralized management, remote access, and business continuity.
Application virtualization decouples software applications from the underlying OS and hardware, encapsulating them into virtual packages accessed from centralized servers on demand. This helps isolate apps from conflicts between components and libraries on the underlying OS.
Microsoft App-V, VMware ThinApp, Citrix XenApp, and Parallels RAS are among the well-known app virtualization and application delivery solutions. Benefits include simpler deployment, mobility, cross-platform delivery, and managing complex compatibility dependencies.
Network Function Virtualization (NFV)
NFV shifts networking functions traditionally tied to specialized hardware appliances into software running on virtual machines on standardized servers. This includes functions like firewalls, intrusion detection and prevention systems, load balancing, network address translation, and more. Benefits include lower costs, easier management and provisioning, and less reliance on proprietary hardware.
This groups existing physical storage from multiple network storage devices into single logical storage pools for simplified storage management and workload balancing. Benefits include centralized administration, non-disruptive disk maintenance, and dynamic allocation of storage resources to virtual machines as needed. Platforms incorporating storage virtualization include VMware vSAN, Microsoft Storage Spaces Direct, Dell EMC UnityVSA, HPE Store Virtual VSA, and Nutanix Acropolis.
Advantages of Virtualization
Beyond the main purposes outlined above, virtualization offers numerous advantages:
Makes better use of underlying physical hardware resources through abstraction and workload consolidation. This reduces redundancies and saves costs on new server hardware.
Centralized virtual infrastructure is much easier to manage versus numerous separate servers. This in turn allows IT personnel to focus less on mundane maintenance.
Snapshots, failover clustering, live migration of virtual machines and other business continuity capabilities simplify disaster recovery procedures.
Virtual desktops can provide enhanced data security since data resides on centralized servers and endpoints function as basic terminals. Role-based access is also restricted according to user context.
Virtualization enables higher quality testing and development environments that accurately mirror production systems.
Flexible provisioning of new servers through templates accelerates deployment times for new workloads.
In summary, various forms of virtualization offer simplified management, maximum hardware utilization, workload mobility and continuity tools through resource abstraction. This in turn drives cost savings, productivity and efficiency.
Use Cases and Examples
Some examples of how enterprises employ virtualization include:
Consolidating Physical Servers
Companies may use VMware vSphere or Hyper-V to virtualize multiple standalone application or file servers onto a smaller number of centralized, powerful host servers running multiple virtual machines. This requires less hardware, space and maintenance overhead while maximizing compute resources.
Virtual Desktop Deployments
Organizations can run hundreds of Windows or Linux virtual desktops on a few centralized regional cluster servers for cheaper scaling. Users access their personal desktop over the network from any endpoint device, simplifying access and mobility.
Virtual Application Delivery
Software like Microsoft App-V may allow delivering specific applications accessed through virtual application templates to simplify app testing, mobility, access controls and prevent conflicts between app runtimes and libraries.
Network Functions as Virtual Appliances
Carriers and enterprises could leverage NFV and SDN to deploy virtual security tools, load balancers, firewalls, IDS/IPS devices and packet inspection tools across the network as portable software appliances rather than expensive proprietary hardware locked to physical locations.
Testing and Development Environments
Programming teams can spin up throwaway test Linux containers and Windows or macOS virtual machines matching production infrastructure specifications for application compatibility testing. These are discarded after use since they run isolated from physical resources.
In these examples and countless other use cases, virtualization reduces hardware costs and management overheads while increasing efficiency, continuity and accessibility through versatile, software-abstracted replacements for specialized hardware.
Virtualization abstracts computing hardware, storage, applications and networks into isolated software constructs like virtual machines, containers or logical storage pools. This provides inherent benefits like environment isolation, portability, resource consolidation and disaster recovery tools. It underlies most cloud infrastructures and enables complex systems management.
Enterprises adopt virtualization for maximizing existing infrastructure investments by consolidating workloads among highly utilized hardware for efficiency and savings. Additional advantages include easier testing, mobility, security and continuity capabilities.
In summary, virtualization broadly refers to replacing dedicated physical servers, storage hardware, network appliances and client devices with logical abstractions running software isolated from underlying infrastructure. Multiple techniques power virtualization, including hypervisors, OS-level containers, SDN and storage virtualization tools.
The many forms and purposes of virtualization aim to benefit administrators through easier management and provisioning of robust, versatile environments while providing end-users platform and location independence. Tech and business leaders turn to virtualization for reducing overhead costs, boosting hardware utilization, simplifying maintenance and scaling systems efficiently.
When transitioning to virtual infrastructures, focus on organizational use cases to pick solutions delivering the most management efficiency, continuity benefits and resource utilization improvements.
Frequently Asked Questions
- What are some key business drivers for adopting virtualization?
Some top business drivers include cost savings from consolidating hardware, simpler management at scale, better resilience and mobile access benefits through abstracted workloads.
- What hardware infrastructure do I need for virtualization?
You’ll need one or more newer powerful host servers with excess RAM, storage and network capacity for optimal virtual machine consolidation plus management and departmental/branch infrastructure connections.
- What are the most popular server virtualization platforms?
The top enterprise options include VMWare vSphere/ESXi, Microsoft Hyper-V, Citrix XenServer and Red Hat Virtualization. Many organizations leverage two solutions like Hyper-V and vSphere for robust infrastructure.
- Is virtual desktop infrastructure more secure than physical PCs?
VDI can improve security since data resides on centralized servers with role-based access controls rather than endpoints vulnerable to theft or loss. Additional data protection is easily added to the back end servers as well.
- Which apps benefit the most from application virtualization?
Complex apps with many compatibility dependencies and libraries benefit greatly. App virtualization enhances portability and access while isolating intricate dependencies to prevent conflicts between component versions.
- Can network virtualization replace all dedicated network hardware?
In most cases physical core network infrastructure hardware will still be needed. But many network functions like load balancing, security services, management tools and packet handling can shift to flexible virtual appliances.
- How is storage virtualization different from storage area networks (SANs)?
SANs consolidate storage into shared arrays accessed over dedicated Fibre Channel networks rather than local disks. Storage virtualization abstracts physical disks across SAN, network or local disks into a single virtual pool using volume managers and software RAID tools.
- What common challenges accompany transitions to virtual infrastructures?
Typical obstacles faced include potential initial performance hits from overheads like abstraction and hyperthreading, inadequate hardware resources relative to consolidation densities, and the complexity of re-architecting networks for maximum flexibility.
- What are the most important factors when selecting server hardware for virtualization?
Some key considerations include processor socket count and core/thread count, excess RAM capacity, bus speeds, storage throughput and connectivity. Additional network capacity and 10Gbps speeds also help optimize extensive VM migrations.
- How do you calculate ideal server consolidation ratios for virtual hosts?
Consider server CPUs/cores, applications, target VM sizes, RAM density, network and disk IOPS. Aim for sufficient excess host resources to handle periodic usage spikes. Typical consolidation ratios average 6-8 VMs per host but could go far higher depending on the above.
- Should every server workload be virtualized?
Workloads like highly specialized appliances with dedicated OS kernels and real-time workloads requiring absolute resource dedication for precision generally remain isolated on bare metal hardware since virtualization adds some resource access overheads.
- What tools help manage large virtualization deployments?
Robust management platforms like vCenter Server bring centralized configuration, automation and insight across the virtual data center in one dashboard for infrastructure visibility and everyday VM administration.
- How does live migration of virtual machines work?
Hypervisors like ESXi can directly migrate running VM instances across locations and physical hosts to support infrastructure flexibility, load balancing and failover capabilities with minimal downtime.
- Can containers fully replace virtual machines?
Containers package app environments for easy portability using far fewer system resources than VMs, which bundle entire guest OSes. But VMs provide stronger workload isolation and remain preferred for infrastructure like desktops and standalone server sandboxes.
- How do costs for virtualization licensing compare to running only dedicated infrastructure?
Per-VM licensing, vRAM entitlements and sockets licensing models make precise cost analysis tricky. Overall cost savings stem mostly from server hardware consolidation and smaller physical data center footprints needed after migrating to extensive virtual infrastructure though.
- What are the most popular application virtualization solutions?
Top options include Microsoft App-V for Windows apps, VMware ThinApp also for Windows, Citrix XenApp as part of the company’s digital workspace platform and Parallels RAS for app and desktop delivery.