fusion io tuning for flash

http://dellteam.fusionio.com/load/-media-/2qc40k/docsLibrary/ION_Accelerator_and_Oracle_RAC_RA_(PUBLIC)_v4_Final.pdf

Fusion-io provides an open source script to tune interconnects on the database nodes.

The ION tuner (iontuner) file makes the following changes:

Tuning Block Devices
 Sets the I/O scheduler to noop, which reduces latency and CPU usage when queuing I/O to the backend storage compared to the default scheduler, CFQ, which is tuned for traditional disk I/O.
 Sets the I/O request queue affinity to level 2, which forces I/O to complete on the same CPU where the I/O request was initiated.
 Disables disk entropy contribution.

IRQ Pinning
To minimize data transfer and synchronization throughout the system, I/O interrupts were handled on the socket local to their PCIe device. To provide the best results, the irqbalance daemon was disabled.
IRQs were pinned for each driver that handles interrupts for ION Accelerator device I/O as well as for the InfiniBand drivers that support the Oracle RAC private interconnect. Driver IRQs were identified in /proc/interrupts by the matching IRQ numbers to the driver prefix listed in the same row. The IRQs were distributed between the CPU cores within the
device’s local socket.