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Product acquisition > Backup and recovery - Pg. 179

750 GBs of storage. In 2001, another IDC study found that the average employee was handling about 1.3 TBs of storage. By 2004, the study, which you can read at the following Web site:,289483,sid5_gci769891,00.html indicated the average employee would be handling about 5.3 TBs of storage. If this were left to individual system administrators managing direct-attached storage, not only would it be overwhelming from a scale perspective, but the management of the storage alone would eat up a large portion of the person's time. If you were to consider the number of different storage drivers in a DAS environment, as well as the number of different storage devices, it would be very enlightening and understandable why a simplified SAN is more cost-effective. In a SAN, much of these savings come from the ability to consolidate support and centralize management. And with today's virtualization technologies, SAN-based storage is even more cost-effective from a management perspective. Customer H's new environment, the equivalent of one FTE's time is spent managing over 20 TBs of storage in multiple locations. 11.4.5 Backup and recovery Customer H has been an IBM Tivoli Storage Manager shop since the mid 1990s. Initially, when the number of servers was limited, the implementation was accomplished using multiple IBM DAT drives. As the IT infrastructure grew, and the need for better enterprise backups expanded, an IBM 3494 tape library with six SCSI-attached drives was purchased. This dramatically improved the backups for the environment, yet, by next year, it was beginning to become a bottleneck due to its I/O limitations, both at the drive and the connectivity level. During the SAN design sessions, Customer H worked with consultants to come up with a solution to this, and two concepts were offered. The first was to put a black box on the back of each tape drive that would convert the SCSI drives to fiber connectivity. The second was to replace the system with a new fiber-based LTO system. Evaluating the performance specifications of both, storage capacity of both, and most importantly, the cost and ROI, it was determined that migrating to an IBM 3584 library with eight LTO2 drives would provide the best return on investment for the price. One of the key benefits of implementing a fiber-based tape unit is that LAN-free backups could be tested, as well as improving restore times based on the higher bandwidth of the tape library. The availability in the industry of Storage logical partitioning may improve the situation further. Recovery of data in the environment was another issue that Customer H had to review. Prior to the SAN, some systems were backed up to a IBM Tivoli Storage Manager server, while others had system specific backup processes in place. Restoration of data was also problematic, especially with platform upgrades. When the company performed its last file server upgrade, it took on average three days to bring each server online with multiple staff people involved for varying degrees. It also required the system to be down so that no changes were made during the migration. With the SAN in place, server migrations are much simpler, and require fewer resources. When a server that has SAN-connected storage needs to be replaced, often it requires just a move of Fibre Channel cables and an OS-based disk discovery to bring the data back online. This can take a data migration from days, to just a few hours, or sometimes, just minutes. This is a true advantage of simplifying the storage environment. 11.4.6 Environments: Have you seen my electric bill lately? Another disadvantage of DAS is the environmental aspect. In order to accommodate DAS, many servers were over 6-8U, meaning that only four servers could be placed in a rack. Over time, this created a space shortage in the primary data center, as well as power issues, since Chapter 11. Infrastructure Simplification in action 179