Linux Tuning Optimization

1) Commands to check current settings before updating sys parameters

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cat /proc/sys/fs/file-max

ulimit -n

cat /proc/sys/net/core/rmem_default
cat /proc/sys/net/core/wmem_default

cat /proc/sys/net/core/rmem_max

cat /proc/sys/net/core/wmem_max

/sbin/ifconfig -a

eth0      Link encap:Ethernet  HWaddr 

          inet addr: Bcast: Mask:

          inet6 addr: fe80::250:56ff:febf:7f5a/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:9313376 errors:0 dropped:0 overruns:0 frame:0

cat /proc/sys/kernel/shmmax 

cat /proc/sys/vm/nr_hugepages 

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2) Edit /etc/sysctl.conf and append these values

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# Set File Max
set fs.file-max=102642

# Increase default socket send and receive buffers
net.core.rmem_default=262122

net.core.wmem_default=262122

net.core.rmem_max=262122

net.core.wmem_max=262122

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3) Edit /etc/sysconfig/network-scripts/ifcfg-eth0 and append MTU
# recommended for gigabit ethernet to reduce packet fragmentation

MTU=9000

4) echo 2147483647 > /proc/sys/kernel/shmmax or update sysctl.conf

5) echo 1000 > /proc/sys/vm/nr_hugepages

6) Edit /etc/limits.conf and set ulimit value