Virtual machines (VMs) are generating a lot of buzz in the telecom industry. They allow multiple independent instances to exist simultaneously on a physical server, thereby reducing maintenance costs, power consumption and cooling demands for businesses. These tools are made possible with what’s called a hypervisor.
What’s the hype?
A hypervisor, otherwise known as a virtual machine monitor (VMM), is a software program that enables users to host numerous VMs on a single piece of computer hardware. Its main purpose is to fulfill the needs of guest operating systems running on a host machine, and ensuring those guest operating systems do not interrupt each other. Specifically, a hypervisor distributes the memory, bandwidth and disk storage space for VMs. Since a hypervisor stands between the hardware and operating systems, several operating systems can run on the same hardware platform.
Hypervisors are by no means a recent technological innovation. The term was originally coined in 1956 by IMB to describe software programs allocated by BM RPQ for the IBM 360/65. Linux and Unix played a significant role in the acclaim for hypervisors today. Back in 2005, Linux and Unix began using hypervisors to broaden the performance of hardware. Nowadays, hypervisors are indispensable to virtualization initiatives.
Type 1 versus type 2
Currently, hypervisors serve as the bedrock of virtual applications. Hypervisors fall within two major camps: type 1 and type 2.
A type 1 runs on the host’s hardware to manage resources and the VMs on it. Examples include VMware ESXi, Citrix XenServer and Microsoft Hyper-V hypervisor. Type 2 runs as a second layer while the operating systems run as a third layer atop the hardware. Examples include Virtage hypervisor, VirtualBox and VMWare Workstation.
Determining which type is best is dependent on an individual’s needs. A type 1 hypervisor is faster than a type 2 hypervisor since the former communicates directly with the server hardware. A type 1 hypervisor does not have to deal with the operating system and various layers that typically encumber hosted hypervisors. A type 1 hypervisor is also more secure than a type 2 hypervisor.
Type 2 hypervisors were more popular when the virtualization movement began to pickup momentum. These hypervisors are compatible with an array of hardware since they use software-based virtualization. For instance, a type 2 hypervisor can be installed on a laptop much easier than a type 1 hypervisor. In addition, type 2 hypervisors are easier to set up since they work directly with an operating system.
Cloning and replication
The bulk of contemporary hypervisors are used for large scale server deployments and to test out various operating systems. They also may be used in data services for cloning and replication.
Hypervisor-based replication was developed to address the technical and business hurdles anchored to virtualized infrastructures. VMs are difficult to replicate with traditional methods. For example, a storage system-based replication method replicates an entire volume of VMs, which demands a large storage space. Hypervisor-based replication frees up storage space by enabling users to select which VMs they want to replicate.
This type of replication reduces data loss, cost and resource utilization. It does this by seizing modifications made to data in real time, which are then replicated to a disaster recovery platform. Since the hardware and storage doesn’t have to be replicated, hypervisor-based replication can significantly improve service levels.
Security issues
Since hypervisors control all of the resources of the hardware, they are a bullseye for hackers. Hypervisors are particularly susceptible to malicious code fed by rogue VMs. According to the provocative insights of the Gartner Analyst Neil MacDonald, approximately 35% of server virtualization vulnerabilities are connected to hypervisors.
MacDonald recommends viewing the hypervisor as the most susceptible operating system in a data center. If a hypervisor is used to separate distrustful code running in a VM from the rest of the system, exploitation of a VMM vulnerability breaks down the barrier, giving hackers access to all the resources of the hardware. Users ought to be aware of and manage these vulnerabilities to keep their network secure.
Conclusion
Hypervisors have become an essential part of the virtualization movement that is rocking the telecom industry. Web servers will continue to use hypervisors to increase resource utilization and decrease costs. Businesses ought to consider advantages and vulnerabilities in choosing which type works best for them.
