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Tuning Other I/O Configurations

Purpose

You can adjust scheduling and I/O parameters to improve the system performance in I/O-intensive tasks.

Procedure

Create a shell script, copy the following code to the script, and execute the script.

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#! /bin/bash

echo 3000 > /proc/sys/vm/dirty_expire_centisecs
echo 500 > /proc/sys/vm/dirty_writeback_centisecs

echo 15000000 > /proc/sys/kernel/sched_wakeup_granularity_ns
echo 10000000 > /proc/sys/kernel/sched_min_granularity_ns

systemctl start tuned
sysctl -w kernel.sched_autogroup_enabled=0
sysctl -w kernel.numa_balancing=0

echo 11264 > /proc/sys/vm/min_free_kbytes
echo 60 > /proc/sys/vm/dirty_ratio
echo 5 > /proc/sys/vm/dirty_background_ratio

list="b c d e f g h i j k l m"
for i in $list
do
  echo 1024 > /sys/block/sd$i/queue/max_sectors_kb
  echo 32 > /sys/block/sd$i/device/queue_depth
  echo 256 > /sys/block/sd$i/queue/nr_requests
  echo deadline > /sys/block/sd$i/queue/scheduler
  echo 2048 > /sys/block/sd$i/queue/read_ahead_kb
  echo 2 > /sys/block/sd$i/queue/rq_affinity
  echo 0 > /sys/block/sd$i/queue/nomerges
done

In I/O-intensive scenarios such as WordCount, you are advised to use the mq-deadline scheduler for improved performance. For configuration details about this scenario, see WordCount (I/O- + CPU-intensive).