While discussing about server virtualization, it is common practice to involve consolidation by putting physical workloads on one physical box. Separation in multiple physical workloads is handled by barriers of virtual machine. In fact, workload consolidation is a remarkably important with respect to virtualization. Consolidation is a nice-to-have feature, and should not be used as justification for virtualization. Conversely, virtualization is inevitable conclusions. When workloads are not consolidated, it does not mean that workload would not be virtual. Here are some of the significant reasons that force to virtualize each and every server:
Simplicity & Consistency
Virtualization is considered as an abstraction of hardware. It summarizes hardware and offers a predictable hardware set to operating systems. It is often thought that virtualization adds more complexities, but rather, it makes things simpler. Computers, computer peripherals and operating systems are highly complicated; and virtualization creates standard interfaces that remove layers of complexity and brings simplicity.
Testing & Imaging
One of the remarkable additional features is abstraction of storage and memory, and to take a snapshot of functional systems and save in a file. Imaging feature gives way to many capabilities like to snapshot of system before installation of software, patching and changing configuration. It helps in quick restore if something goes wrong. Though this might look as a negligible feature, it is a key feature and increases the reliability of overall system. Snapshot makes it easy to test various features, repeat testing or roll back to previous versions, and achieve your goals in non production environments.
Snapshot abstraction leads to the ability to keep backups in image based format. Such types of backups help in restoring the system easily and quickly without any additional interface. All hypervisor makers do not add this feature and, therefore, it is important to consider how this feature is added. HyperV has this feature fully; XenServer adds it partially, whereas VMware vSphere adds it with a paid license. If image based backups are offered, they allow a much faster recovery than other forms of backups. It is possible to recover entire system after a disaster in few minutes.
Virtual machines can be treated as files when these are not running actively. This feature helps in migration between dissimilar hardware and physical hosts. Conventionally, hardware upgrade or replacement is a very difficult and risky migration procedure. When contemporary virtualization is used, however, it offers non-destructive and reliable system to move hardware with negligible or zero downtime. Due to virtualization, jobs that were risky and complicated in past have become insignificant today.
Management of Workload
Some virtualization features are appropriate for specific scenarios. Virtualization products offer tools to move workloads between different storage devices or host without facing downtime. Presence of fault tolerant options allows workloads to recover by moving from disastrous hardware to superfluous hardware without interference from users.
There are many additional features of virtualization and one of the significant features is consolidation. Just like other features, consolidation is not considered as central feature. Consolidation is responsible to give flexibility while handling workloads. Virtualization gives standardization, flexibility, stability and manageability. While buying virtualization products, analyze the value of the product against its expenditures.