SANs are great (heres why), but we need a SAN OS

SANs are great (here`s why), but we need a SAN OS

Ahmad Zamer

In today`s business environment, effective utilization of information is vital to the success of any enterprise. To develop competitive advantages, businesses require convenient access to readily available information. Unlike other basic utilities such as electricity and the telephone, accessing and utilizing digital information remains challenging. Fibre Channel storage area networks (SANs) create the infrastructure capable of delivering such a utility, making information available on tap.

This article looks at some of the elements needed to enable a "SAN tone," similar to a telephone dial tone--a universal information access and delivery point.

Fibre Channel technology added momentum to the idea of creating an independent network for storage that is scalable, secure and centrally managed. In addition, it separates the processing of information from its management.

In a SAN environment, storage management and storage-related data traffic are handled by the SAN. Moving storage-related functions and storage-to-storage data traffic to a SAN relieves the local area network of time-consuming tasks such as backup and restore.

In addition, liberating storage devices from servers opens the door for increasing storage capacity as the need arises. It also enhances availability of information, as the SAN storage devices no longer depend on, or are tied to, a particular controlling server.

SANs also promise to enable users to access all information, regardless of physical location. The value of "any-to-any" user access is enhanced by the benefits of centrally managed storage resources to deliver high information availability.

In today`s business environment, promising any-to-any connectivity implies the ability to support and manage information and storage resources in heterogeneous computing environments. This translates into the ability to deal with disparate operating systems, incompatibilities among products from various vendors, and an assortment of storage management tools with different user interfaces. Careful deployment of the SAN building blocks and phased implementation of new SAN capabilities offers the best option.

The ideal storage manager on a SAN would control all local and remote storage devices on the network and allow anyone to access any device regardless of the operating system or applications. A storage manager may use a universal file system that renders the differences among the various operating systems transparent.

A user with a Unix workstation should be able to retrieve and modify a file created under Windows NT, and vice versa. Over time, operating systems will migrate to a unified universal file system, but until then, SAN storage management tools need to provide that functionality.

SAN operating system

For truly independent storage networks to materialize, a SAN operating system that delivers any-to-any connection and continuous availability of storage (a SAN tone) is needed. Implied in the notion of a SAN OS are smarter storage peripherals, application-aware agents, and slimmed-down operating systems. In addition to creating a universal file system, the SAN OS will manage other storage housekeeping functions performed today by traditional operating systems. Such functions include recognition of new storage and setup of storage devices, including formatting of hard drives and creation and management of RAID groups.

Under the new model of a SAN OS, storage-centric devices such as RAID controllers are expected to move out of LAN servers and into storage towers. This move relieves LAN servers from the burdens and overhead associated with monitoring and managing storage devices and traffic, resulting in more efficient LAN performance and higher productivity.

Relegating storage housekeeping tasks to a SAN OS also allows operating systems to get rid of such functions and focus on delivering better productivity on the LAN. Slimmed-down operating systems require slimmed-down application servers and workstations. This translates into significant reduction in future expenditures on these devices.

Server-free backup

It`s hard to talk about SANs without mentioning server-free backup. In fact, at times it seems that server-free backup is the only reason behind the emergence of SANs.

As we continue to edge closer to expecting full access to information on a 24x7 basis, the time for performing backup operations all but evaporates. Server-free backup addresses the need for full-time data availability and a zero-time backup window by relegating all backup tasks to the SAN.

As the name implies, server-free backup entails data traffic among storage peripherals, which in turn assumes smarter storage devices than what we have today. For example, a tape library needs to be intelligent enough to communicate with the hard drives it is expected to back up as dictated by corporate needs and backup schedules.

Smart devices under the supervision of a SAN OS will communicate and perform normal storage functions and disaster recovery operations without user intervention.

Another feature of a SAN OS is the availability of application-aware agents that are tailored to optimize services offered to certain application groups. For example, a digital video agent would detect related traffic and optimize data streaming to deliver flicker-free, uninterrupted video. The digital video agent would also understand the needs of such environments for fast data streaming and would be less concerned about disaster protection, storing the video on a striped RAID group as opposed to utilizing other forms of RAID.

On the other hand, an application server targeting the financial services industry would recognize such transactions and their need for extremely high data protection and disaster recovery and store the information using a RAID-5 group with double redundancy.

Developing a SAN operating system will improve the efficiency of LANs, facilitate the development of smart storage devices, and deliver information on tap by making the elusive storage dial tone a reality.

Ahmad Zamer is a business development manager at Atto Technology Inc. (www.attotech.com), in Amherst, NY. He can be reached at azamer@attotech.com.

This article was originally published on November 01, 1999