Disk virtualization is more popular than ever before. In modern computing, one of the most common forms of virtualization is achieved with a virtual disk. Also known as a logical disk or logical volume, a logical disk doesn’t represent a physical disk in its own right. It either represents a partition of one physical disk or partitions spanning multiple physical disks - depending on how it’s used.
Separating a Single Physical Disk into Multiple Logical Disks
In some cases, you might want to separate a single physical disk into multiple logical disks. This process is typically performed on large hard drives, and usually for the purpose of organization. Keeping your work files on one logical disk and your personal files on another, for example, is a great way of keeping them separated and avoiding confusion.
Advanced users might want to separate a large hard drive into multiple logical disks in order to support multiple operating systems. Users who frequently switch between Windows and Mac platforms, for example, usually use virtual or logical disks to avoid mixing the different system files on the same drive or within the same directory.
Combining Multiple Physical Disks into a Single Logical Disk
Other times, you might want to combine multiple physical disks into a single logical disk. This is often done when you want to combine several small-capacity hard drives to achieve the appearance of a single storage repository.
It's also possible to use a single physical drive as a part of multiple logical drives. By partitioning the physical drive into multiple partitions, you can reserve space that can then be assigned to different logical disks as needed.
Disk Drive Segmentation
The storage space that's been allocated to a logical drive is referred to as a segment. In modern computing, a segment can encompass the entire capacity of one or more physical drives or a portion of one or more physical drives. If the logical drive is deleted at a later date, the reserved disk capacity will be reverted to available space.
Logical Drives in RAID
Some RAID configurations can utilize logical drives, too. It might even include its own level of redundancy, depending on the RAID level and functionality. These RAID-based logical drives can be protected even further with the use of hot spare drives. Generally speaking, RAID-based logical drives can be adjusted after creation. This lets you expand its capacity or even modify the RAID configuration level.
Logical Drive Risks
While logical drives are generally beneficially in many ways, they do have some risks. Systems that have too many virtual or logical drives will eventually run into data latency and throughput issues as they navigate the various layers of virtualization, which will have a negative effect on overall system performance. Other risks to consider include backing out of a failed implementation, lack of software support on virtualized devices, and more.
Using Logical Drives
Now that you have a better understanding of logical drives and their common applications, you'll be able to determine the approach that is best for you, your hardware, and your computing requirements. Use this information to your advantage and begin optimizing your system today.
You may read more about logical disks in Wikipedia: Logical disk.