Measures reported by UspDrrProcTest

A Data Recovery and Reconstruction Processor (DRR) is a microprocessor located on the DKAs that is used to generate parity data for RAID-5 or RAID-6 parity groups. The DRR uses the formula "old data + new data + old parity" to generate new parity.

If the monitor data shows high DRR usage overall, this can indicate a high write penalty condition. Please consult your Hitachi Data Systems representative about high write penalty conditions. If the monitor data shows the imbalance usage of the DRR, you should consider relocating volumes using Volume Migration to balance DRR usage within the subsystem.

This test is used to identify the usage of the DRR Processor.