Example sysctl.conf file
The following example of a sysctl.conf file shows settings that have been used in testing.
/etc/sysctl.conf
Tip: Optimize Cassandra and ElasticSearch Kernel parameters by either disabling Swap, or
setting the Kernel vm.swappiness parameter to
1.To customize your sysctl.conf file, first back-up the original file, then edit it, before
restarting the system. The default location is
/etc/sysctl.conf
# sysctl settings are defined through files in
# /usr/lib/sysctl.d/, /run/sysctl.d/, and /etc/sysctl.d/.
#
# Vendors settings live in /usr/lib/sysctl.d/.
# To override a whole file, create a new file with the same in
# /etc/sysctl.d/ and put new settings there. To override
# only specific settings, add a file with a lexically later
# name in /etc/sysctl.d/ and put new settings there.
vm.swappiness = 1
vm.dirty_background_ratio = 3
vm.dirty_ratio = 80
vm.dirty_expire_centisecs = 500
vm.dirty_writeback_centisecs = 100
kernel.shmmax = 4398046511104
kernel.shmall = 1073741824
kernel.sem = 250 256000 100 16384
net.core.rmem_default = 262144
net.core.rmem_max = 4194304
net.core.wmem_default = 262144
net.core.wmem_max = 1048576
fs.aio-max-nr = 1048576
kernel.panic_on_oops = 1
fs.file-max = 6815744
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_max_syn_backlog = 4096
net.ipv4.tcp_syncookies = 1
net.core.somaxconn = 1024
kernel.shmmni = 16384
net.ipv4.ip_local_port_range = 9000 65535
kernel.msgmnb = 65536
kernel.msgmax = 65536
kernel.shmmax = 540971653120
kernel.shmall = 4294967296