Tiered Storage: Does Your Data Know Its Place?

Recent legislation, such as the Sarbanes-Oxley Act and the Health Insurance Portability and Accountability Act (HIPAA), is forcing companies to retain information at a much faster rate and in vastly greater amounts for much longer than ever before. In addition, that information must be more readily accessible, making tape less practical. These requirements are forcing IT organizations to rethink their storage strategies. No longer can companies think of meeting their escalating storage needs only in terms of tape or undifferentiated disk. Tape does not meet performance or reliability requirements, and brings with it onerous management and IT staffing issues. Fast, reliable disk, on the other hand, may be too expensive to meet all compliance requirements.

One new technology that shows much promise for satisfying these new requirements is Serial Advanced Technology Attachment (SATA). SATA is a serial interface to the ATA disk drive that builds on the success of Parallel ATA but offers improved performance and reliability, as well as reduced interface complexity. Equally important, SATA continues the considerable cost advantage and raw capacity of Parallel ATA over Fibre Channel (FC) and SCSI drives.

Organizations cannot simply start using SATA instead of tape, however. Now, more than ever, it is vital to carefully plan what kinds of information should be stored on which types of storage media and when, if ever, that information should be moved from one type of storage media to another. To address these issues, a systematic methodology called Information Lifecycle Management (ILM) has been developed out of several commonly accepted practices. One central component of ILM is the tiered storage model, which calls for using storage media with different characteristics for delivering multiple, differentiated levels of service.