Storage Consolidation — Part 1— Design

Peter Baer Galvin

Regardless of the new technologies that promise decreasing storage needs, those needs keep increasing. Whether it is user files, databases, human resources information, or research results, disks keep getting filled. The trend toward consolidated storage is strong and getting stronger. This month in the Solaris Corner, I’ll discuss the business needs for consolidated storage, provide a process for designing a storage solution, and look at the two leading solutions: SAN and NAS. Next month, in part 2, I will cover the implementation of consolidated storage, including some complexities you may not expect.

Unfortunately for facilities managers, but fortunately for technology providers, storage solutions keep advancing and increasing in complexity. Not long ago, a site would run a combination of direct-attached storage (DAS) and network file services (NFS or CIFS). Occasionally there was dual-attached storage to enable high-availability clustering. Anyone requiring more connections generally installed a proprietary central-storage unit (e.g., an EMC Symmetrix). Disk spindles were spread across these devices, leading to the need for separate management and capacity planning. Spindles were wasted because extra capacity was needed in each set of storage.

The Storage Evaluation

With the advent of storage switches, there is a new solution where DAS would have been used. A SAN consists of one or more storage switches, connecting hosts and storage. The benefits of this new model are many, as are the complications. The first step in a storage consolidation project is a storage evaluation:

• Tools such as the Sun HighGround can be installed on all storage-centric systems to evaluate how much space is used and free throughout a facility. It can also tell how much is “old” and “new” to determine whether HSM would be useful.<>