Chapter 16
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Managing the Storage Infrastructure 375
Creation of zone or LUN is an example of an information alert. Warning alerts require administrative attention so that the alerted condition is contained and does not affect accessibility. For example, when an alert indicates a soft media error on a disk that is approaching a predefined threshold value, the administrator can decide whether the disk needs to be replaced. Fatal alerts require immediate attention because the condition may affect overall performance or availability. For example, if a disk fails, the administrator must ensure that it is replaced quickly. Alerts can be assigned a severity level based on the impact of the alerted condition. Continuous monitoring, in conjunction with automated alerting, enables administrators to respond to failures quickly and proactively. Alerting provides information to prioritize administrator’s response to events.
16.2 Storage Management Activities All the management tasks in a storage infrastructure can be broadly categorized into availability management, capacity management, performance management, security management, and reporting.
16.2.1 Availability management The critical task in availability management is establishing a proper guideline for all configurations to ensure availability based on service levels. For example, when a server is deployed to support a critical business function, the highest availability standard is usually required. This is generally accomplished by deploying two or more HBAs, multipathing software with path failover capability, and server clustering. The server must be connected to the storage array using at least two independent fabrics and switches that have built-in redundancy. Storage devices with RAID protection are made available to the server using at least two front-end ports. In addition, these storage arrays should have built-in redundancy for various components, support backup, and local and remote replication. Virtualization technologies have significantly improved the availability management task. With virtualization in place resources can be dynamically added or removed to maintain the availability.
16.2.2 Capacity management The goal of capacity management is to ensure adequate availability of resources for all services based on their service level requirements. Capacity management provides capacity analysis, comparing allocated storage to forecasted storage on a regular basis. It also provides trend analysis of actual utilization of allocated