Tuning Linux Kernel

Edit /etc/sysctl.conf to make changes persistent.

Less Swapping

To set it:

sudo sysctl vm.swappiness=10

Check it

cat /proc/sys/vm/swappiness

Set in /etc/sysctl.conf:

vm.swappiness = 0

Adjust Cache

For IO server allow more dirty pages, less dirty cache:

• Kernel Tuning for Kafka
• Better linux disk caching performance

defaults:

$ sudo sysctl -a | grep -i 'vm.dirty'
vm.dirty_background_bytes = 0
vm.dirty_background_ratio = 10
vm.dirty_bytes = 0
vm.dirty_expire_centisecs = 3000
vm.dirty_ratio = 20
vm.dirty_writeback_centisecs = 500
vm.dirtytime_expire_seconds = 43200

In /etc/sysctl.conf set:

vm.dirty_background_ratio = 5
vm.dirty_ratio = 80

IPv6

I see no reason not to set in /etc/sysctl.conf:

net.ipv6.conf.all.disable_ipv6=1
net.ipv6.conf.default.disable_ipv6=1