Storage Area Network Backup
By Brocade Communications Systems, Inc. (Issue 1 2001) Storage area networks (SANs) provide a powerful framework for building and managing storage systems, allowing simplified management and increased fault tolerance in a scalable architecture. This article highlights some of the advantages of implementing SANs. A storage area network (SAN) is a networked storage infrastructure designed to provide a flexible environment in which servers may be decoupled from storage devices. SANs accomplish this by using Fibre Channel switch fabric technology, commonly referred to as the SAN fabric, to connect servers to storage devices. SANs address today's most challenging business requirements: protecting and accessing critical data, using computing resources more efficiently, and ensuring the highest levels of business continuance. Traditional approaches to backup and recovery
As enterprise data becomes an increasingly essential business asset, ensuring its stability and protection is more critical than ever. Many organizations have faced the challenge of having to back up growing data within shrinking backup windows. Some have found themselves unable to cost-effectively back up all their data as consistently as they would like. Instead, they have been forced to devise different backup strategies for various types of data, depending on their importance. Traditionally, backup and recovery models have featured dedicated disk and tape systems for each host server, with each host backing up its own data to its own locally attached tape drives or library (see Figure 1 ). This design uses tape resources poorly—even if one server's tape drive is idle, another server cannot use it.
Figure 1. A traditional backup and recovery model with dedicated storage resources In addition, each operating system platform tends to use unique backup and recovery software applications, which complicates management and the backup and recovery process. Disk and tape systems tend to be slower, less reliable, and smaller than enterprise storage systems, because most organizations cannot afford to dedicate faster, more reliable storage resources to individual servers. Another traditional, but more efficient, approach to backup and recovery involves a primary backup and recovery server, which controls tape resources (see Figure 2 ). The backup server receives data from other servers across a LAN or wide area network (WAN), then stores that data on centrally owned disk and tape resources. This centralized approach uses tape resources more effectively, while making deployment of faster, more reliable tape drives and libraries more cost-effective.
Figure 2. A traditional backup and recovery model over a LAN The primary drawback of this approach is the introduction of potential network bottlenecks for the backup and recovery process. Using the primary LAN or WAN to perform backup and recovery can potentially degrade performance for production workloads running on the same network. Improved backup and recovery
In contrast, SANs can simplify the data backup and recovery process and help ensure fast and timely backup and recovery. The switched, 100 MB/sec full-duplex capabilities of Fibre Channel fabrics can significantly improve backup and recovery performance. SAN-based backup and recovery scenarios are often referred to as "LAN-free." Removing the LAN from the backup and recovery process can provide a variety of advantages. SAN-attached tape drives and libraries can be implemented so that each server sends its own backup data directly to the shared tape resources instead of through the network to the backup server. The SAN enables bulk data transfer from each server to shared SAN storage, while the LAN is used only for communication (not data) traffic between the servers (see Figure 3 ). The result is a fast, scalable, and reliable backup and recovery solution, which uses storage, server, and LAN resources effectively.
Figure 3. A SAN-based LAN-free backup and recovery model Advanced scalability and manageability
SANs provide a framework for indefinitely scaling up the server and storage infrastructure as the number of users or workload increases—without necessarily inhibiting performance. This approach enables deployment of new storage resources without disrupting operations throughout the system. Many organizations start with a relatively modest server configuration and add new servers with or without associated storage. As the number of nodes in the network grows, more switches are added to the network. To simplify administration, the fabric automatically learns the network topology. SANs improve storage resource management through centralization, even within distributed information technology (IT) architectures. For example, SAN software tools enable organizations to allocate storage to various hosts, replicate that data, back it up, and monitor it on a continual basis. Remote disaster recovery capabilities
The ability to protect and recover data—and quickly get systems back online following a disaster—is a critical component of any high-availability networking model. SANs are ideal in environments where data must be automatically transferred to a remote facility for disaster recovery purposes. As a result, SAN-based disaster recovery configurations can provide efficient backup and recovery, extended distance connectivity, and additional fault tolerance. A disaster recovery solution depends on the organization's specific requirements. Obviously, many types of businesses cannot afford even minutes of downtime without significant consequences. Other organizations might be able to tolerate downtime of a day or longer. As a result, disaster recovery plans need to account for particular availability requirements as well as IT equipment, network configuration, staffing, and overall processes. SANs can be an integral part of a disaster recovery solution, by protecting data over long distances in hot-standby or mirrored configurations and by enabling long-distance, electronic tape-vaulting solutions. Native Fibre Channel technology provides the 10 km or greater link-extended distance connectivity required to maintain geographically separate disaster recovery facilities or mirroring operations. In large fabric configurations, SANs can use WANs or metropolitan area networks (MANs) to cover long distances (see Figure 4 ). Figure 3. A SAN-based LAN-free backup and recovery model Advanced scalability and manageability
SANs provide a framework for indefinitely scaling up the server and storage infrastructure as the number of users or workload increases—without necessarily inhibiting performance. This approach enables deployment of new storage resources without disrupting operations throughout the system. Many organizations start with a relatively modest server configuration and add new servers with or without associated storage. As the number of nodes in the network grows, more switches are added to the network. To simplify administration, the fabric automatically learns the network topology. SANs improve storage resource management through centralization, even within distributed information technology (IT) architectures. For example, SAN software tools enable organizations to allocate storage to various hosts, replicate that data, back it up, and monitor it on a continual basis. Remote disaster recovery capabilities
The ability to protect and recover data—and quickly get systems back online following a disaster—is a critical component of any high-availability networking model. SANs are ideal in environments where data must be automatically transferred to a remote facility for disaster recovery purposes. As a result, SAN-based disaster recovery configurations can provide efficient backup and recovery, extended distance connectivity, and additional fault tolerance. A disaster recovery solution depends on the organization's specific requirements. Obviously, many types of businesses cannot afford even minutes of downtime without significant consequences. Other organizations might be able to tolerate downtime of a day or longer. As a result, disaster recovery plans need to account for particular availability requirements as well as IT equipment, network configuration, staffing, and overall processes. SANs can be an integral part of a disaster recovery solution, by protecting data over long distances in hot-standby or mirrored configurations and by enabling long-distance, electronic tape-vaulting solutions. Native Fibre Channel technology provides the 10 km or greater link-extended distance connectivity required to maintain geographically separate disaster recovery facilities or mirroring operations. In large fabric configurations, SANs can use WANs or metropolitan area networks (MANs) to cover long distances (see Figure 4 ).
Figure 4. A MAN with native Fibre Channel connections over longer distances For many organizations, storage area networks (SANs) may provide a more effective approach to storage management, backup, and recovery than traditional dedicated storage. Fibre Channel fabrics with Brocade® switches provide scalable, managed storage services that allow virtually unlimited data storage on a "pay-as-you-grow" basis. Brocade Communications Systems, Inc. (info@brocade.com) is a leading supplier of Fibre Channel fabric solutions for storage area networking. For more information
For more information, service, or support, please visit www.brocade.com For white papers about storage area networks (SANs), please visit www.brocade.com/SAN/white_papers.html For more information, please contact info@itmsltd.net |
