Managing Virtual Storage

The virtual machine (VM), which is a computer program requires storage to store its data. To enhance the overall performance of the VM administrators can make use of virtual storage in order to present one physical or network-based storage device in multiple types of storage. The VM can then access it without having to know the hardware.

Managing virtual storage requires the careful balance of performance, capacity and cost. Admins need to decide if they prefer to only use solid-state drives or hard-drive disks. They also need to determine the type of storage controllers and how many they will implement. IT managers can cut down on storage costs by using compression and deduplication.

There are three types of virtual storage: physical disks, RAID groups, and logical volumes (LV). Physical disks and RAID group divide the physical capacity into smaller units that applications or servers perceive as one storage device. A virtualization layer manages I/O requests from the server and translates them to the correct physical storage disk.

The virtual storage model reduces hardware expenses by separating the operating system from physical devices and providing an administration point that is a single source. It also provides scalability by automatically adapting the physical capacity to meet demand. It also allows administrators to perform a variety tasks in a non-disruptive manner for example, moving data from over-utilized devices. This is done using the technique of data migration. The mapping granularity determines the speed at which meta-data updates can be made, the amount of much space will be required during migration and how quickly a previous location can become free.