Guest Column: How Deduplication Helps Reduce The Cost Of Backup And Disaster Recovery

By Kay Benaroch and Shane Jackson

Today's explosive data growth is prompting many organizations to look for ways to increase the efficiency of their storage, backup, and disaster recovery processes. The growth of data is straining capacity, but at the same time, cost and complexity frustrate many IT managers seeking to make improvements. For example, tape-based approaches that worked well when originally implemented can prove to be slow, expensive, and unreliable as the organization grows and as tapes must be physically transported from remote sites to a central storage location. Disk-based backup is inherently faster and more reliable than tape, but has traditionally been more costly, and large disk arrays can be difficult to manage.

Comparing physical capacity to logical capacity illustrates the value of integrated deduplication in Dell/EMC DD Series appliances. The physical capacity is the amount of raw storage provided by the disks in a particular system. Some of this storage is consumed by appliance operations such as RAID and spares; subtracting this amount from the physical capacity yields the usable capacity, to which the expected deduplication ratio is then applied. Multiplying usable capacity by the deduplication ratio yields the expected logical capacity—the amount of backup data an administrator can keep on the system after deduplication, depending on change rate, retention policies, and other factors.