A hypervisor is a process or a function to help admins isolate operating system and applications from the underlying hardware. Cloud computing uses it the most as it allows multiple guest operating systems (also known as virtual machines or VMs) to run simultaneously on a single host system. Administrators can use the resources efficiently by dividing computing resources (RAM, CPU, etc.) between multiple VMs.
A hypervisor is a key element in virtualization, which has helped organizations achieve higher cost savings, improve their provisioning and deployment speeds, and ensure higher resilience with reduced downtimes.
The Evolution of Hypervisors
The use of hypervisors dates to the 1960s when IBM deployed them on time-sharing systems and leveraged them for testing new operating systems and hardware. During the 1960s, virtualization techniques were extensively used by developers wanting to test their programs without affecting the main production system. The mid-2000s witnessed another significant leap as Unix, Linux, and others experimented with virtualization. With advancements in processing power, companies built powerful machines capable of handling multiple workloads. In 2005, CPU vendors started offering hardware virtualization to their x86-based products, making hypervisors mainstream.
Why Use a Hypervisor?
Now that we’ve answered “what is a hypervisor,” it’ll be useful to explore some of their important applications to better understand the role hypervisors play in virtualized environments. Hypervisors simplify server management as VMs are independent of the host environment. In other words, the operation of one VM doesn’t affect other VMs or the underlying hardware. Therefore, even when one VM crashes, others can continue working without affecting performance. It allows administrators to move VMs between servers, a useful capability for workload balancing. As teams migrate VMs from one machine to another without stopping them, they can use this feature for fail-over. Moreover, a hypervisor is useful for running and testing programs across different operating systems.
However, the most important use case for hypervisors is to consolidate servers on the cloud. Data centers require server consolidation to minimize server sprawl. In fact, virtualization practices and hypervisors have become popular because they’re highly effective in solving the problem of underutilized servers. Instead of running different workloads on separate physical servers, virtualization enables administrators to easily leverage the unused hardware capacity to run multiple workloads simultaneously. They can match their workloads with proper physical resources, meeting their time, cost, and service level requirements.
What Are the Different Types of Hypervisors?
- Type 1 Hypervisors (Bare Metal or Native Hypervisors): Type 1 hypervisors are deployed directly over the host hardware. Direct access to the hardware without any underlying OS or device drivers makes such hypervisors highly efficient for enterprise computing. The implementation is also inherently secure against OS-level vulnerabilities. VMware ESXi, Microsoft Hyper-V, Oracle VM, and Xen are examples of type 1 hypervisors.
- Type 2 Hypervisors (Hosted Hypervisor): Type 2 hypervisors run as an application over a traditional OS. Developers, security professionals, or users who need to access applications only available on select OS versions often rely on type 2 hypervisors for their operations. KVM, VMware Server and Workstation, Microsoft Virtual PC, Oracle VM VirtualBox, and QEMU are some popular type 2 hypervisors.
The Need for a Virtualization Management Tool
Today, most enterprises use hypervisors to simplify server management, and it’s the backbone of all cloud services. While virtualization has its benefits, IT teams are often under-equipped to manage a complex ecosystem of hypervisors from multiple vendors. It’s not always easy to keep track of different makes of hypervisors and accurately monitor the performance of VMs. Moreover, the ease of provisioning increases the number of applications and operating systems, which further increases routine maintenance, security, and compliance burden.
Moreover, VMs may still require IT support concerning provisioning, de-provisioning, and auditing according to varying security and compliance mandates. Troubleshooting often involves skimming through numerous product support pages. As organizations scale up, lack of access to proper documentation and technical support can make implementation and management of hypervisors difficult. Eventually, controlling virtual machine sprawl becomes a significant challenge.
Different groups within an organization often deploy the same workloads over different clouds. This increases inefficiency and complicates data management. IT administrators have to employ virtualization management tools to solve the above challenges and manage their resources efficiently.
Virtualization management tools provide a holistic view of all VMs, their states (running, stopped, etc.), and the availability of host servers. These tools also help in performing basic maintenance, provisioning, de-provisioning, and migration of VMs.
Key Players in Virtualization Management
There are three broad categories of virtualization management tools available in the market:
- Proprietary tools (with varying degree of cross-platform support): VMware vCenter, Microsoft SCVMM
- Open-source tools: Citrix XenCenter
- Third-party commercial tools: Dell Foglight, SolarWinds Virtualization Manager, Splunk Virtualization Monitoring System
As listed above, the tools offered by vendors such as VMware and Microsoft are specific to their hypervisors and offer limited compatibility with other hypervisors. Most organizations prefer third-party commercial tools for virtualization management as these tools offer better cross-platform support, deeper analytics, reporting, and other helpful features.
For instance, SolarWinds Virtualization Manager helps control VM sprawl with simple reports highlighting the top 10 VMs by snapshot disk usage, orphaned VMDKs, powered-off VMs, and more. It also provides help in capacity planning by providing predictions on CPU, memory, network, and storage needs.
Further, SolarWinds offers a visual dashboard called PerfStack™ within VMAN’s virtual machine monitor. It helps administrators pull performance metrics from their network, VMs, storage, and database and monitor these metrics over a single chart.
As most organizations now prefer a hybrid environment, IT teams are often overburdened with multiple tickets, alerts, and have to monitor numerous dashboards to resolve issues. With a capable virtualization management tool, teams can reduce this complexity and manage their resources better. Most of these tools have evolved to offer advanced features for managing cloud and on-premises virtual environment over a single interface, thereby making the most of the IT ecosystem.