Managing Virtual Storage

The virtual machine (VM), which is a computer program requires storage to store its data. Virtual storage is a way to enhance the performance a VM by providing a single physical storage device or network-based storage in different types. The VM can access it without knowing about the underlying hardware.

Virtual storage management requires a careful balance between performance, capacity and costs. Admins need to decide if they prefer to use only solid-state drives, or also hard-drive disks. They should also decide on the kind of storage controllers and how many to put in place. IT managers can cut storage costs by using compression and deduplication.

There are three kinds of RAID groups: logical volumes (LV) and physical disks. Physical disks and RAID groups divide physical capacity into smaller units, which applications or servers perceive to be one storage device. A virtualization layer transforms I/O requests sent by the server to the right physical disk.

The virtual storage model lowers hardware expenses by separating the operating system from physical devices and by providing an administration point that is a single source. It also offers scalability through automatically changing the amount of physical capacity to meet the demands. Additionally, it permits administrators to handle a variety of tasks in a non-disruptive manner such as moving data off over-utilized storage devices. Data migration is a method that allows this to be done. Generally, the mapping granularity determines how quickly meta-data can be updated, how much additional space is required during the migration and how quickly the previous location can be marked as free.