Data Storage Virtualization

Chapter 6, “Data Storage in the Cloud,” discussed cloud-based data storage in detail. You learned that cloud-based data storage has the following advantages:

• Scalable disk-storage space on demand

• The ability to “pay as you go” for the storage needed

• Behind-the-scenes backup and data replication

• Support for common operating systems

• Access from anywhere, anytime, and essentially any device

• Ease of document sharing

Cloud-based storage has the following primary disadvantages:

• Some users are not comfortable with their data residing in the cloud.

• Cloud-based file access is slower than local-file access due to network overhead.

Data-storage virtualization essentially separates the physical-data storage from the logical presentation that users (and applications) use to access the device. For example, users will often partition a large (physical) hard drive into two more logical drives (often drives C and D).

The process of making a device available to a user or application is called mounting the device. Several cloud-based data-storage provider allow users to mount the virtual storage so that the user can refer to the storage area using a familiar disk-drive letter.

Again, as shown in FIGURE 8-14, the data-storage virtualization hides the physical details of the actual storage device, which makes it very easy for administrators to scale the available storage space.