ENVISION Integrates Online, Near Online, And Offline Storage.

This article is the second in a two-part series. The first part appeared in the June issue of CTR.

The ENterprise VIrtual Storage Integration Over Networks (ENVISION) architecture allows delineation and integration between online, near online, and offline storage. As the Intelligent Virtual Tape Storage Device (IVTSD) contains the storage management policies and its agents poll the storage devices attached to the architecture, it manages the migration of unused, inactive data from disk storage to near-online tape storage--in this case, the IVTSD--or to offline storage, which is physical tape.

The introduction of Fibre Channel (FC) technology helps make serverless backup possible. FC configurations allow users to create enterprise-capable storage networks where most, if not all, production data servers can attach to a common storage pool via 100MB/sec fibre-optic cables. SAN technology enables users to segregate storage from servers and build high performance, reliable, and scalable storage networks. It also enables data replication, remote copying or remote mirroring to hotsites with either IVTSDs or automated tape libraries that can be located up to 120km away.

The "intelligence" within the IVTSD is a key component of the architecture, as it removes the backup operation from the server without the addition of new software. It also provides the ability to quickly make "offline" backups of data without using excessive CPU cycles, memory, or server I/O. The Intelligent Virtual Storage Management Application (IVSMA) uses the data provided by the deployed agents and user-defined policies to determine where to place data within the storage architecture. By leveraging "snapshot" backup technology, which is essentially taking an instant, point-in-time image of the data, ENVISION backs up data several times a day without adversely affecting production data availability.

The IVSMA resides within the IVTSD firmware. It communicates with any backup application using a standard data management protocol (e.g., Network Data Management Protocol) and initiates its operation when invoked by the backup application. It also advises the backup application of operational status and manages data synchronization and updating, data and tape cataloging, and automatic migration of inactive data to offline storage without using CPU overhead.

This approach to policy-based backup dramatically improves not only backup performance, but also network application and server performance without affecting production servers or the network. The architecture is also advantageous from a deployment and management standpoint. Instead of attaching multiple physical tape storage devices to the SAN, attaching an IVTSD can provide the host and applications with 64 or more unique tape devices without the cost, installation, or footprint of additional physical devices. Supported back-end tape backup devices may be direct-attached to the IVTSD or the SAN via Fibre Channel and gateways and the tape library cost and footprint is greatly decreased by the inherent volume-stacking ability that virtual tape storage provides.

Costs And Benefits

Eliminating the server from the backup process results in immediate performance and cost benefits. Data throughput is determined by the speed of the storage devices--not by the processing power of the server--so the backup window virtually disappears and productivity levels improve significantly. CPU overhead is also reduced, as one IVTSD takes the place of many high-end servers and dedicated tape servers. ENVISION architecture also enhances productivity by freeing up servers previously dedicated to backup. Data integrity is increased because data can now be backed up more frequently. Disaster recovery can be performed much more easily and quickly because the most recent backups are automatically replicated, mirrored, or copied in the IVTSD cache or in near-online tape devices located at the designated hotsites.

Total Cost Of Storage (TCS)

The total cost of storage (TCS) consists not only of the capital invested in computing and storage devices, connectivity, and media, but also of the costs of operating the environment. There are additional, hidden costs associated with storage: network and CPU utilization, device maintenance, and storage management. The ENVISION architecture will reduce TCS by addressing the following cost factors:

* Investment Protection. ENVISION allows the use of previously dedicated application servers to meet increased performance requirements. It provides the ability to reallocate released storage and to add or to decrease storage dynamically without disrupting current activities. It also allows leveraging of existing storage devices by attaching them to the SAN through FC-SCSI bridges or FC-ESCON gateways.

* Cost Reduction. An inherent benefit of SAN-attached storage is the consolidation of data from heterogeneous server-attached storage devices into a centralized storage pool. This capability allows more cost-effective deployment of storage through standardization on a single storage solution for the enterprise. Consolidation also reduces facilities and device maintenance expenses through the reduction of the storage footprint and optimization of physical device usage. Through the automation and centralization of manual storage management tasks, ENVISION also lessens the need for additional staffing. CPU usage costs decrease because it takes the backup operation off the server. ENVISION not only reduces the need to purchase additional physical tape transports and media, but also minimizes downtime by reducing the number of physical devices and the need for adding or reconfiguring physical capacity because the virtual architecture can represent 64 or more virtual tape drives.

Improved Performance

Performance is improved because of the optimized use of resources. Eliminating the application server from the backup process frees that server to perform application-specific operations. Using FC allows data transfers of up to 100MB/sec. In a tape library environment, most data retrievals occur within 24 to 48 hours of when the data was created. Integrated storage management policies take this into account and keep those virtual volumes resident in the cache, so that when a retrieval request occurs, data is retrieved at disk access speeds. Even if the data requested from the host is not in the cache, the logical volume may be quickly retrieved from near-online tape storage, uploaded into the cache, and, then, transferred to the host. ENVISION would also improve storage performance in other areas, including:

* Application Performance. Application performance is greatly improved through faster access and response for I/O- and storage-intensive applications. ENVISION also achieves high-availability requirements through improved device RAS and architecture redundancy. As application servers are freed up, response time, availability, and service level delivery are improved owing to reduced batch windows and additional server I/O capacity.

* Storage Management. ENVISION enables virtually transparent, faster, automated data migration between layers of the storage hierarchy. Tape device utilization is improved and backup and recovery operations can now accommodate shrinking backup windows. The ability to perform multiple methods of data replication allows for the restoration of individual files, if necessary. The Storage Resource Management (SRM) component also provides a consolidated interface that streamlines backup administration.

* Network Capacity and Bandwidth. ENVISION improves network performance by removing data traffic from the LAN, reducing congestion and bandwidth bottlenecks.

* Increased Productivity. ENVISION separates users from performance, availability, and space management tasks and provides higher levels of server and tape storage performance, greatly improving productivity, and the centralization and automation of storage management prevents the duplication of effort that occurs when users, application developers, and system administrators all manage their own storage.

Concept Only, Now

ENVISION is currently a conceptual architecture, since some of the necessary components needed to deploy the solution are either not yet available or not robust enough to be integrated into the architecture. In order to make ENVISION a reality, the following enabling technologies will be required:

* Concurrent support for multiple operating systems, file systems, and applications.

* Logical partitioning (zoning) on the IVTSD to provide enhanced data protection and security to prevent unauthorized access to shared data.

* IVTSD support of native FC connectivity.

* The ability of the IVTSD to manage data as data, regardless of file structure or format.

* The ability to restore data without having to first go through the IVTSD cache.

* Policy management that is robust and well-defined at both the management level (SRM) and the virtual device level.

* Integration with existing backup, storage management, and monitoring software.

* Further development and integration of multi-vendor SAN configurations that provide data center-class RAS.

* Development of APIs for existing storage management software in order to fully exploit ENVISION capabilities and enable further development.

While some of ENVISION's enabling technologies are not yet in production, it is important to begin the planning process now. As with any technology solution, it is critical that the IT organization meet with customers and potential vendors to ensure that the solution will complement business objectives and meet or exceed customer requirements. Risks should be identified and assessed to determine their potential impact and a thorough cost/benefit analysis should be undertaken. These pre-implementation planning activities should be performed in the following order:

* Requirements Identification and Definition. This should be a detailed, business-centric assessment that includes analysis of current business plans and operational functions, as well as current and future storage requirements. This assessment results in a storage management requirements document that can be shared with users, management, and vendors, ensuring that storage requirements are properly identified across the enterprise.

* Gap Analysis. This will provide a clear understanding of current storage management operations and requirements and any gaps between the two, as well as future storage requirements. The analysis will determine what is needed to close the gaps between current storage capabilities and future storage requirements. Areas covered would include data selection and migration plans, system sizing, and failover requirements.

* Technology Impact Analysis. Although changes in technology can be risky, the best strategy is to plan for the introduction and deployment of new technology within the environment. Understanding the potential risks and how the environment could be affected by the deployment of new technologies is key in planning for implementation of any new technology.

* Technology Evaluation. Once current and future requirements are known and the impacts and risks are identified and assessed, an indepth evaluation of the technology is necessary. This evaluation should include a detailed, step-by-step comparison of the requirements definition to technology features and functions. A cost/benefit analysis, including total cost of ownership and return on investment, should be performed, as well. Once selected, the solution should be brought into the user environment and tested under a full range of workloads designed to emulate as accurately as possible the current and future production environments.

* Implementation. Once the technology has been selected and tested, it must be implemented in the production environment. Implementation includes installation, testing, configuration, tuning, migration, changes in format, etc. Documentation must be written or updated and administration and operations personnel must be trained.

Glenn Jacobsen is the senior partner at Trilliant Group (Denver, CO), a vendor-neutral consulting, integration, and education firm focused exclusively on storage and storage management.