What is a virtual machine (VM)?

• Virtual Machine Definition

  Virtual Machine Definition

  A virtual machine (VM) functions in a virtual environment and utilizes the resources of a physical machine, such as memory, CPU, network interface, and storage. The primary purpose of a virtual machine is to operate multiple systems virtually from a single device.
• How does a virtual machine work?

  How does a virtual machine work?

  Virtual machines are virtual environments that work as physical machines within a computer. The physical machines on which virtual machines run are known as host machines. VMs run as an isolated partition on its host computer wherein it uses power, CPU, operating system (Windows, Linux, macOS), and other resources. End-users can run multiple virtual machines on a single computer. The entire process is managed by a software hypervisor. The role of a hypervisor is to allocate and distribute resources to VMs, for instance, storage and memory from the hosts. While running multiple virtual machines, the hypervisor schedules operations so that resources do not overrun each other.

  There are mainly two types of hypervisors, known as Hypervisor 1 and Hypervisor 2. Type 1 hypervisors are bare metal and often found in server-based environments like data centers. With this type of hypervisor, VMs can utilize host resources directly. Hypervisor 2 is a hosted hypervisor that runs solely on the host's operating system. Unlike bare metal, Hypervisor 2 is not bound to physical hardware to utilize its resources, making it independent and suitable for businesses that do not have dedicated servers for virtualization.
• What are virtual machines used for?

  What are virtual machines used for?

  Organizations prefer using virtual machines due to the benefits of deploying virtual desktop infrastructure (VDI). VDI deployments help users and organizations access desktop environments like Linux and Windows. There are plenty of reasons to use virtual machines, and they offer several benefits, including efficient IT systems, security, scalability, and cost savings.

  • Security: Security is one of the primary reasons why businesses prefer using VMs over host machines. Virtual environments and operating systems are isolated within the host operating system. This helps boost the security of VMs and protects them from vulnerabilities, such as malware and cyberattacks, and makes VM an ideal choice for production tasks, including application and software testing. Disaster recovery is another major reason why organizations prefer VMs. Virtual machines can easily be reverted to older versions, deleted, and recreated.
  • Cloud computing: Organizations can take advantage of hybrid clouds by quickly deploying and migrating cloud-native virtual machines to on-premises servers and vice-versa. Businesses can tweak their cloud services in real-time to improve scalability depending on the requirements and varying usage levels. Additionally, developers can also create ad hoc virtual environments in the cloud using virtual machines to test their implementation.
  • Cost efficiency: One of the significant advantages of using virtual machines is that users can host multiple operating systems on a single server. Instead of investing in multiple operating systems, organizations can deploy one server and various applications, leveraging physical hardware at its maximum capacity, thereby improving cost efficiency.
  • Scalability: Deploying a virtual machine is as simple as creating copies of operating systems. All you need is a physical machine to install virtual operating systems and get started. Utilizing a virtual machine helps organizations respond better to fluctuations and help stabilize the performance of the teams. The process of installing a virtual machine is fast and efficient compared to installing different operating systems on other physical servers.
• Business benefits of virtualization

  Business benefits of virtualization

  Businesses can run several virtual machines on a single server depending on the performance resources such as CPU, RAM, and storage. Outlined below are the significant benefits of using a virtual machine.

  • Faster deployment: Deploying a physical server involves time-consuming steps such as server installation, dependency resolution, resource optimization, security checks, and more. In contrast, virtualization is a quick process involving deployment of a virtual server using a secure pre-configured server template.
  • Reduced hardware costs: Virtualization allows you to convert a physical machine into several virtual machines that reduce the requirement of purchasing multiple hardware resources. It also reduces the ongoing support and maintenance costs, eliminates the need for infrastructure space to store the hardware devices, and human resources to handle them.
  • Portability and migration: Virtual machines are significantly easier to move across the virtual environment or from one physical server to another. On the other hand, moving a physical server is a resource-intensive task involving data transfer and hardware re-allocation and re-installation.
  • Increased IT operational efficiency: Virtual machines increase IT operational efficiency by reducing the time you spend managing routine administrative tasks. As virtualization involves partitioning one physical machine into multiple virtual servers, it becomes easier to deploy, operate, and manage them.
  • Improved security and disaster recovery: As virtual machines make several copies of their operational history, it becomes easier to extract and retrace the information whenever required. This also reduces the risk of data loss in case of an unexpected hardware failure. Additionally, virtualization allows you to enhance the overall security with fewer systems to manage and a smaller infrastructure to maintain and handle.
• When is using a VM a better option?

  When is using a VM a better option?

  You can use a virtual machine to investigate, add, or upgrade your servers, including hardware and software. This not only helps save your time and efficiency but also protects your business-critical data and applications by creating an automatic backup. However, to successfully install a virtual server on a physical host machine, you need a hypervisor (like VMware or Microsoft Hyper-V).
• Disadvantages of using VMs

  Disadvantages of using VMs

  Although virtual machines are quite effective, shifting network responsibilities onto virtual machines introduces a new set of concerns and issues. These issues may include compatibility and configuration issues and the different allocations of software and hardware required for the virtual machines to function. Outlined below are a few challenges and limitations of VMs:

  • Configuration issues: The virtual environment of your organization changes constantly to accommodate evolving applications and new virtual machines. This frequent change in configurations can lead to performance issues and time-consuming VM sprawl that can be difficult to control and manage.
  • Compatibility issues: It’s important to have a virtualization-compatible host machine to establish a virtual server. Some IT infrastructures don’t support virtualized solutions or don’t have the appropriate resources to establish a virtual connection.

  Failures in a virtualized set-up can lead to performance and efficiency losses that can be costly to fix and address. It’s important to have the right virtual machine software and performance monitor in place to help monitor and keep track of the health of a virtualized environment through centralized dashboards.
• Virtual machines and virtualization differences

  Virtual machines and virtualization differences

  Virtualization can be defined as the process of creating virtual machines on a physical host server using software known as a hypervisor. A hypervisor can be defined as a virtual machine monitor to create and run VMs. It helps in operating multiple virtual machines as guests on a host server and makes it possible to maximize the use of the system's available resources such as CPU, network bandwidth, memory, and so on. A hypervisor can help you create an abstraction layer over the physical server to efficiently run multiple virtual servers, operating systems, and applications on it.

  On the other hand, virtual machines act as individual machines with their own operating systems and applications but use the resources of their physical host to perform the functions.
• Types of VMs

  Types of VMs

  For installing different virtual operating systems, including Windows, Linux, and Mac on a host machine, you must use virtual machine software, such as Windows virtual machine software, Linux virtual machine software, Microsoft virtual machine software, virtual machine backup software, and more. Outlined below are the two most common types of virtual machines:

  1. System virtual machines: System virtual machines provide full virtualization and act as a real machine. These VMs share and manage host hardware resources to function and execute the entire operating system, thereby creating multiple virtual environments on the host system. These multiple VMs are isolated and allow sharing of resources such as memory via memory pages. A system virtual machine requires a virtualization software known as a Virtual Machine Monitor (VMM) for its implementation.
  2. Process virtual machines: These virtual machines are also known as application virtual machines and are used to run applications inside the operating system of a physical host. They offer high-level abstractions and platform-independent programming environments to the entire process. Moreover, they require interpreters or runtime software for their successful implementation and are also known as managed runtime environments. The best examples of process virtual machines are parallel virtual machines, message passing interface, and Java virtual machines used for Java programming.
• Types of virtualization

  Types of virtualization

  To integrate virtualization, it’s important to understand the different types of virtualization. Outlined below are the five types of virtualization processes you can use based on your specific business requirements.

  1. Desktop virtualization: Desktop virtualization allows users to access a desktop connected remotely or locally. This type of virtualization is commonly used in digital workspaces and highly depends on application virtualization. Desktop virtualization can be of two types: local and remote virtualization. Local desktop virtualization refers to how virtual machines run on a client device where all the workload is on the local hardware. On the other hand, remote desktop virtualization refers to the process that operates in a client/server computing environment. In this type of virtualization, all the interactions take place on a client device. This type of virtualization offers centralized security control, allows you to work remotely, and manages resources.
  2. Application virtualization: Application virtualization allows you to use and gain access to the application installed on a separate computer. The applications can be virtualized following the server-based approach. This approach lets you install the application on a host machine that can be delivered to the other connected desktops using application virtualization software. This type of virtualization can be used to install, manage, maintain, patch, or update applications across your organization by using a central server. 
  3. Server virtualization: Server virtualization creates multiple isolated virtual server instances that can independently run separate operating systems. This is one of the best ways to use the existing resources of your IT infrastructure. Moreover, it can help you provide web hosting services. The key benefits of server virtualization include reduced operating costs, increased application performance, high server availability, reduced complexity, and less workload. There are types of server virtualizations:
     
     • Full virtualization: Full virtualization uses a hypervisor.
     • Para-virtualization: Uses the entire network as a cohesive unit.
     • OS-level virtualization: Uses the virtualization capability of the operating system running on a physical server. This method doesn’t use a hypervisor.
  4. Network virtualization: Network virtualization refers to how hardware, software, and network functionalities are combined into a single virtual network. This type of virtualization helps you keep track of various elements such as switches and routers in your network infrastructure. It offers flexibility, reliability, security, and scalability to your network. It simplifies the allocation and distribution of resources, improving network efficiency and productivity.
  5. Storage virtualization: Storage virtualization is a technique used to centralize the physical storage of multiple storage devices to facilitate data backup, archiving, data recovery, and more. Storage virtualization helps make your network infrastructure system more flexible, convenient, and scalable.
• VM vs. containers differences

  VM vs. containers differences

  A major key difference between virtual machines and containers is that VMs let you run multiple virtual servers with different operating systems on a single host, whereas containers offer high-density application virtualization with the ability to scale up and down.
• Why are VM host monitors important?

  Why are VM host monitors important?

  Virtual machine host monitors are the software applications that can monitor VM host metrics to track the health and performance of your virtual environment. VM host monitor is an important tool that helps minimize downtime. As soon as the host monitor identifies a performance issue within your virtual environment, it sends real-time alerts to notify respective teams about which metrics have exceeded the threshold limit. With this quick monitoring process, IT administrators can quickly identify bottlenecks before they start affecting end-user experience. Thereby providing a better web application experience. VM host monitors are capable of:

  • Identifying shortages of memory and capacity within your VM host: Memory and capacity can be a source of downtime in a VM host environment. VM host monitors help you identify these bottlenecks by keeping track of total memory capacity and consumed memory.
  • Monitoring CPU metrics using CPU monitors: CPU metrics are crucial to monitor to detect excessive CPU usage. These metrics help you understand the percentage of CPU used, virtual CPU capacity available, and the number of CPU cores available.
  • Receiving metrics to ensure disk health: Excessive read and write data can lead to end-user downtime without the right preventative measures. Read and write monitors help you measure the amount of data read and written from/ on your virtual disk.

  Virtual machines can add efficiency and reliability to your organization without any overhead costs. As VMs can accommodate multisystem operations from centralized control, users can easily switch to multiple operating systems. VMs also keep historical data of their operations and offer rapid disaster recovery in the event of hardware failure.
• What does a VM monitoring tool offer?

  What does a VM monitoring tool offer?

  VM monitoring tools provide comprehensive insights to consolidate and centralize useful observations. It can also collect critical performance details and allows you to drill down to specific metrics such as CPU usage, storage, and memory usage for deeper analysis. Moreover, the advanced alerting system helps you stay up to date regarding notifications, activities, performance, and events. These tools also allow you to perform a real-time performance analysis of the virtual machines.