
11.1 What is the challenge?
In recent years we have seen an increasing speed in developing new storage servers which can compete with the speed at which processor development introduces new processors. On the other side, investment protection as a goal to contain Total Cost of Ownership (TCO), dictates inventing smarter architectures that allow for growth at a component level. IBM understood this early on, introduced its Seascape® architecture, and brought the ESS into the marketplace in 1999 based on this architecture.
11.1.1 Speed gap between server and disk storage
Disk storage evolved over time from simple structures to a string of disk drives attached to a disk string controller without caching capabilities. The actual disk
11.1.2 New and enhanced functions
Parallel to this development, new functions were developed and added to the next generation of disk storage subsystems. Some examples of new functions added over time are dual copy, concurrent copy, and eventually various flavors of remote copy and FlashCopy. These functions are all related to managing the data in the disk subsystems, storing the data as quickly as possible, and retrieving the data as fast as possible. Other aspects became increasingly important, like disaster recovery capabilities. Applications demand increasing I/O rates and higher data rates on one hand but shorter response times on the other hand. These conflicting goals must be solved and are the driving force to develop storage servers such as the new DS6000 series.
With the advent of the DS6000 and its
These storage servers grew with respect to functionality, speed, and capacity. Parallel to their increasing capabilities, the complexity grew as well. The art is to create systems which are well balanced from top to bottom, and these storage servers scale very well. Figure
220DS6000 Series: Concepts and Architecture