Adapter FCoE Performance Tuning
The following FCoE driver parameters affect adapter performance:
Operation Mode
Interrupt Delay Timer
Execution Throttle
Frame Size (Fibre Channel)
Queue Depth
The default values for Frame Size and Execution Throttle provide maximum performance for most environments. The following subsections describe how to use the Operation Mode, Interrupt Delay Timer, and Queue Depth parameters to improve adapter performance.
Operation Mode (ZIO)
This parameter specifies the reduced interrupt operation (ZIO) modes. ZIO modes post multiple command completions in a single interrupt. The effects of tuning this parameter are remarkable only when the I/O being serviced by the adapter is transactional (small block size I/O operations). Experiment with Operation Mode and Interrupt Delay Timer values in a test environment before applying the changes to a production environment.
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Value | Description |
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0 | Disable Operation Mode |
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5Mode 5 causes DMA to transfer response queue entries into the response queue. No interrupt is generated unless the Response Queue
6Mode 6 causes DMA to transfer response queue entries into the response queue, and an interrupt is generated when the firmware has no active exchanges, even if the interrupt delay timer has not expired.
Interrupt Delay Timer (zio_timer)
This parameter is valid if the Operation Mode parameter is enabled. It specifies the interval, in 100ms increments, between the time that the response queue is updated to the time that the interrupt is generated. The interrupt is not generated if the host updates the Response Queue
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