The challenge
Storage area networks (SANs) enable companies to share homogeneous storage resources across the enterprise. But for many companies, information resources are spread over a variety of storage and server environments, often using products from different vendors. This can result in a multitude of file systems that need to be managed individually, which can increase complexity, require a variety of skilled resources, and make it difficult to implement consistent policies for file and database management. Also, file and data administration tasks often impact application availability. All this can lead to poor utilization of storage resources, high costs and reduced business efficiency. Why? Because today's file systems do not exploit the benefits of SANs.

Companies need the ability to share their storage resources across multiple vendor devices and platforms, to simplify file and data management, and perform storage administration without impacting data and application availability. As their information storage needs continue to rise rapidly, companies continue to operate on lean budgets and staffing. The best solution is one that leverages existing IT investments and provides growth when needed. It is a solution that helps exploit the benefits of SANs by improving data sharing and providing easy and efficient access to data. It is a solution that eliminates the need to create duplicate files, pools storage capacity, and maximizes utilization of file and database storage across the SAN, while increasing efficiency, application availability and administrator productivity.

IBM TotalStorage SAN File System
The IBM TotalStorage SAN File System is intended to provide a common file system specifically designed for storage networks. It is intended to help businesses maximize the benefits of SANs. A key element of its design is the way that it manages the metadata-overall information about files such as file location, security permissions and locks. In many traditional file systems, the metadata resides within individual servers, which can create limitations in sharing and accessing data across servers or across file systems. By managing the metadata on the storage network using a metadata server, instead of within individual application servers, the design of SAN File System helps move intelligence out of individual servers onto the storage network so that it can be available to any application server on the network. The SAN File System Client software runs on the application servers, and interacts with the SAN File System metadata server to get the metadata. Once the SAN File System Client software has the metadata, it then accesses the file data directly via the SAN. In this manner, SAN File System is designed to provide high-performance access to data and enable sharing across heterogeneous application servers. SAN File System is designed to allow applications on any server within the SAN to access any file in the network. No changes to the applications need to be made.

Designed to help simplify file and data management and improve administrator productivity
SAN File System provides a central point for managing data and storage for application servers in your SAN. By providing a single file system across the SAN, it is designed to provide: consistent implementation, management and monitoring of policies; central capacity planning, monitoring and management; and enablement of backup and recovery from a single backup server in a consistent manner. It is designed to provide alerts and allow you to define and easily change storage usage limits with hard and soft quotas for logical subsets of the file system called Filesets. It is designed to help you to easily manage storage requirements that change over time.

The SAN File System supports centralized policy-based storage management by providing a facility that lets you group storage volumes into storage pools where all of the volumes in a storage pool have common characteristics such as performance, redundancy, backup requirements or costs. You can define storage pools to represent differentiated classes of service for different business areas or storage users based on your business needs. SAN File System is designed to allow you to manage the storage within each storage pool as a unit and add to, remove or change the storage as needed, transparent to the application servers. You can then define the rules or "policies" for determining what files are placed in the storage pools, so that files are allocated to the storage pools that match the class of service that they require. You can use any of the file attributes (such as file name, file type, date created, user ID or group ID, and so on) to create these rules. Through the use of the policy-based rules, the SAN File System automates the task of allocating space on the desired storage volumes.

Simplifies server consolidation and data migration
SAN File System is designed to help simplify application-server consolidation and improve administrator productivity by reducing or eliminating the need for data migration or by improving the ease of moving data. Since data can be shared across servers, it doesn't need to be migrated along with the application or server. SAN File System is designed to help you to grow available space with minimal or no disruption.

Designed to help improve application and data availability
SAN File System is designed to help improve application and data availability by reducing or eliminating application downtime for file and data management tasks, backups, and additions and changes of storage devices.

SAN File System can help provide you with the freedom to perform file and data administration tasks when needed and with little or no downtime-instead of having to schedule around rapidly shrinking windows of planned downtime. It is designed to enable nondisruptive additions and changes of storage devices. And it can help reduce planned downtime by providing application-server-free backups. SAN File System is designed to allow you to perform quick and minimally disruptive backup and recovery of all or a portion of the file system with file-based IBM FlashCopy functionality. It can also help you consolidate backup agents to a single designated backup server-removing backup workloads from application servers.

Designed to help simplify data sharing, and improve ease and efficiency of access to data SAN File System is designed to pool together the file space of multiple and disparate file systems in your SAN environment to produce a SAN-wide file system with a single global namespace. By providing a single, consistent file system that can be accessed by all servers on the SAN, SAN File System can help simplify and enhance file sharing and access across multiple servers and operating systems. The SAN File System Client is designed to support full file locking as well as byte-range locking to coordinate across multiple users accessing the data simultaneously. SAN File System is designed for high scalability to support growth of the number of files or the storage capacity that can be supported.

Designed to help improve storage utilization
SAN File System is designed to pool storage capacity across multiple server and storage platforms on the SAN, and help improve storage utilization. It is designed to provide a common pool of file space that can be accessed and used by any server on the SAN File System.

SAN File System pools free file space and temporary space across the SAN to help increase storage-capacity utilization. It is designed to help reduce storage usage by reducing or eliminating the need to maintain multiple copies of applications and files for data sharing and access.

Technology for an on demand era
SAN File System supports open standards and includes a Common Information Model (CIM) agent that supports storage management by certain products based on open standards. Thus, certain other vendor products that comply with the open standards of the Storage Network Industry Association (SNIA) CIM can also manage the SAN File System. The SAN File System Client-Metadata server protocol and a reference implementation of the SAN File System Client for Linux have been published and are available at ibm.com/storage/sfs-protocol.

• Virtualisation can help reduce complexity, treating storage and IT resources as a single, common pool of resources SAN File System is designed to help pool together your disparate file systems and simplify the access and management of data on the SAN, effectively virtualising your file-storage environment. It is designed to allow the management of capacity on demand and make business data available to any server in the enterprise.
   
• Autonomic capability can help simplify file and data management, and improve staff productivity SAN File System allows you to define rules that automate provisioning of storage. It is designed to provide active monitoring and aggregation of status into a dashboard, and allow you to find and resolve issues quickly. It enables you to automate routine file and data management tasks and increase the effective capacity managed by an administrator.

 
IBM services
IBM offers services designed to help speed implementation and return on investment (ROI). IBM specialists are available to conduct solution and infrastructure reviews to help prepare for and speed initial installation. And IBM Global Services can examine existing infrastructures to determine sizing and performance needs. In addition, you can choose from a range of service and subscription offerings to help keep your infrastructure up to date and running smoothly.

For more information
To find out more about SAN File System and other high-performance IBM products, contact your IBM representative, call IBM Direct at 1 800 IBM-CALL (1 800 426-2255) or go to ibm.com/totalstorage/virtualization.