Hitachi 9900 manual An Overview of High-availability HA Computing Software

Hitachi Freedom Storage™	7
Lightning 9900™ V Series

Availability Is Highest in the Industry

An Overview of High-availability (HA) Computing Software

It is increasingly important for a business to support continued access to global information 24/7. What’s more, careers often depend on the availability of service levels provided by IT to the enterprise.

In computer science, availability refers to the degree to which a system or resource is capable of performing its normal function. Availability is measured in terms of Mean Time Between Failure (MTBF) divided by MTBF plus the Mean Time to Repair (MTTR).

•AVAILABILITY = MTBF / (MTBF+MTTR)

For example, a server that fails on average once every 5,000 hours and takes an average of two hours to diagnose, replace faulty components, and reboot, would have an availability rating of 5,000/(5,000 + 2) = 99.96%. This would correspond to a Level 3 rating using the Scale of 9s.

Software Products Contribute to High-availability Computing

Many factors can cause unplanned downtime. The Hitachi Freedom Storage™ Lightning 9900™ V Series has been designed to eliminate as many of these factors as possible in hardware redundancy, online replaceable components, and software data copy functions. This allows copies of data at other locations either locally or remotely so that processing can continue in the event of an outage.

Backup and restore procedures and products also contribute dramatically to computer system availability by reducing the time to restore operations in the event of an outage.

Hitachi has teamed with industry-leading storage management software providers, such as VERITAS® Software, to provide world-class high-availability solutions. These solutions contribute to the fact that customers and analysts alike regard Hitachi Freedom Storage systems as having the highest availability in the industry.

The Lightning 9900 V Series Has an Advanced Availability Profile Compared to Competitive Products

The Lightning 9900 V Series was designed with maximum emphasis on high- availability computing for today’s most critical enterprises, including:

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•System microcode that can be upgraded nondisruptively

•Active/active dual-ported disk drives instead of single-port drives or active/passive dual-ported drives

•Redundant active components throughout the system, combined with automatic failover architecture

3With the exception of Seagate® HDD microcode.

Availability refers to the degree to which a system or resource is capable of performing its normal function.

Customers and analysts alike regard Hitachi Freedom Storage systems as having the highest availability in the industry.

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