The virtual machine (VM) is a computer program requires storage for its data. Virtual storage can be used to improve the performance of a VM by providing a single physical storage device or network-based storage in different types. The VM can access it without needing to be aware of the hardware.
Virtual storage management requires the careful balance of capacity, performance and cost. Admins must decide whether to make use of all solid-state disks or hard-drive disks, what kind of storage controllers to use; and how to combine them in a hybrid configuration. To reduce costs, IT managers should consider storage reduction capabilities such as deduplication and compression.
There are three types of virtual storage: physical disks RAID groups and logical volumes (LV). Physical disks and Raid groups split physical capacity into smaller units that applications or servers interpret to be one storage device. A virtualization layer transforms I/O requests made by the server to the right physical disk.
The virtual storage model lowers hardware cost by separating out the operating system from the physical devices and providing a single point of administration. It also facilitates scalability by automatically altering the physical capacity to meet demand. It also allows administrators to accomplish a variety of tasks in a non-disruptive manner for example, moving data from over-utilized devices. This is done using the technique of data migration. 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 declared free.
https://duediligencedataroom.blog/what-is-the-role-of-a-virtual-storage-manager/