linux优化

1254780221

#!/bin/bash
###Centos6.5_64##############################
###############系统包安装############################################
yum install -y net-snmp ntp openssh-clients  gcc gcc-c++ openssl-devel vim lrzsz unzip rsync
chkconfig snmpd on
/usr/sbin/ntpdate time.windows.com
echo "*/15 * * * * /usr/sbin/ntpdate -u pool.ntp.org >/dev/null 2>&1" >> /var/spool/cron/root

########修改ssh默认端口为22########################################
echo -ne "
Port 22
" >>/etc/ssh/sshd_config
sed -i 's/^GSSAPIAuthentication yes$/GSSAPIAuthentication no/' /etc/ssh/sshd_config
sed -i 's/#UseDNS yes/UseDNS no/' /etc/ssh/sshd_config
service sshd restart
###修改SELINUX=disabled#########################
sed -i '/SELINUX/s/enforcing/disabled/' /etc/selinux/config
setenforce 0
service ntpd start
chkconfig ntpd on
service iptables stop
chkconfig iptables off
##############################################
ulimit -SHn 65535
echo -ne "
* soft nofile 65535
* hard nofile 65535
* soft nproc  65535
* hard nproc  65535
" >>/etc/security/limits.conf
##############################################
echo -ne "
net.ipv4.ip_forward = 0
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.default.accept_source_route = 0
kernel.sysrq = 0
kernel.core_uses_pid = 1
kernel.msgmnb = 65536
kernel.msgmax = 65536
kernel.shmmax = 68719476736
kernel.shmall = 4294967296
net.ipv4.tcp_max_tw_buckets = 60000
net.ipv4.tcp_sack = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_rmem = 4096 87380 4194304
net.ipv4.tcp_wmem = 4096 16384 4194304
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.core.netdev_max_backlog = 500000
net.core.somaxconn = 262144
net.ipv4.tcp_max_orphans = 3276800
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 262144
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_synack_retries = 1
net.ipv4.tcp_syn_retries = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_mem = 94500000 915000000 927000000
net.ipv4.tcp_fin_timeout = 1
net.ipv4.tcp_keepalive_time = 1200
net.ipv4.tcp_keepalive_probes=5
net.ipv4.tcp_keepalive_intvl=15
net.ipv4.ip_local_port_range = 1024 65535
net.nf_conntrack_max = 25000000
net.netfilter.nf_conntrack_max = 25000000
net.netfilter.nf_conntrack_tcp_timeout_established = 180
net.netfilter.nf_conntrack_tcp_timeout_time_wait = 120
net.netfilter.nf_conntrack_tcp_timeout_close_wait = 60
net.netfilter.nf_conntrack_tcp_timeout_fin_wait = 120
vm.swappiness = 0
" >>/etc/sysctl.conf
modprobe bridge
sysctl -p
###############删除优化脚本###############
rm -f /tmp/youhua.sh

lvs

。。。

mayiwen123456

优化哪几项，优化之后有什么好处，写清楚一点，让我们这些新手也能快速的理解，谢谢！