Is it necessary to have a SAN and NAS model? In the near term , both storage networking models will be with us. As we continue to support the present application mix of OLTP- and batch-type workloads, it's necessary to provide an optimized access method. This will continue to drive the segregation of data between file and block level access and require increased duplication and overhead. The results will be a continuation of storage demand and growth, albeit an inflated use of resources.
The future of SAN/NAS integration will be driven by the increased need to utilize existing data for multiple purposes or applications. The slowing of duplication requirements is a critical requirement for any integrated front-end storage access method. As some applications require file access from remote locations, other local applications will require read/write access on a fundamental block I/O level. The ability to provide these access levels through a combined storage network utilizing a file or block access will be the next storage system.
What is missing today are the components to make that happen. Figure 20-8 shows a future configuration where an integrated file system serves as both file- and block- level access to a common storage network. Future components that will facilitate this solution will be a shared file system with storage network coherency, increased state- aware disk devices, and real-time fault resiliency in recovery fabrics . The storage network components will communicate with storage access appliances that serve applications with either block or file access. Applications will log in and register with the storage network regarding their preferences for recovery, access, and security.
In looking toward the future, use caution when developing storage networking configurations. The useful life of storage networking technologies has only been a year and a half in the short end and three years in the long term. The point must be made that we remain at the forefront of storage innovations that will be increasingly vulnerable to both changes in microprocessor technologies and the evolving universe of web services.