Q-Logic 8200 SERIES manual High-Availability Configuration

2 – General Description Supported Network Configurations

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2.3.3

High-Availability Configuration

High availability describes a system that is operational a high percentage of the time. Through dual redundancy, a system can maintain high availability in the presence of any single component failure.

Use of redundant components, multipathing, and failover help protect against failures and ensure high availability. Implementing SVM agents on SANbox SSP provides high availability by allowing the use of multiple paths between servers and storage, and ensuring that no single point of failure can prevent access to data.

Failover is a backup operational mode in which the functions of a system component (such as, a server, network, or storage controller, for example) are assumed by secondary system components when the primary component becomes unavailable through either failure or scheduled down time.

With the proper multipathing software running on the host, a high-availability configuration can guarantee access to data even in the event of one or possibly more hardware, software, or infrastructure failures. With the addition of multiple hosts running supported clustering software, even host failures can be tolerated without interrupting critical applications.

In addition to continuous operation through unplanned failures, a correctly set up high-availability configuration enables administrators to take components of the system offline for maintenance or replacement, again without interrupting access to data.

Figure 2-4shows a recommended high-availability configuration with cross-connected fabric. Within each fabric, zoning is used to partition the front-side initiator ports, both StoreAge SVM ports, and back-side storage. Each server has multiple HBAs installed, with at least one HBA connected to each of two redundant front-side fabrics. Each HBA sees the same virtual disks on each of two redundant SANbox SSPs. Each SANbox SSP has access to physical storage through at least two paths, across two fabrics and at least two RAID controllers. Two SVMs can each manage either or both SANbox SSP units. Two independent fabrics and host failover software ensure availability.

2-6 SN0054628-00 A