SAN Volume Controller: Best Practices and Performance Guidelines

Chapter 5.3.1. ESS

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Chapter 5. Storage controller 63 See Chapter 15, “ Troubleshooting and diagnostics” on page 259 for information regarding checking the back- end paths to storage controllers. 5.1.2 Ensuring path balance prior to MDisk discovery It is important that LUNs are properly balanced across storage controllers prior to performing MDisk discovery. Failing to do so can result in a suboptimal pathing configuration to the back- end disks, which can cause a performance degradation. Ensure that storage subsystems are in a dual- active state and that all LUNs have been distributed to their preferred controller ( local affinity) prior to performing MDisk discovery. Pathing can always be rebalanced later, however, often not until after ...