优化linux系统
1.关闭selinux
2.关闭ipv6
3.Ip6tables 停止启动
4.Ssh修改为20443
5.Ssh 客户端开启
6.修改sysctl.conf
7.Ulimit 调高
关闭selinux
1.Vi /etc/sysconfig/selinux
SELINUX=disabled
CentOS 6.3 禁用ipv6
1. Vi /etc/modprobe.d/disable-ipv6.conf
install ipv6 /bin/true
2.Vi /etc/sysconfig/network
IPV6INIT=no
Ip6tables 停止服务，不启动
Service ip6tables stop
Chkconfig –level 2345 ip6tables off
修改ssh端口
1.Vi /etc/ssh/sshd_config à Port 20443
2.Vi /etc/ssh/ssh_config à Port 20443
优化sysctl.conf
1.mv /etc/sysctl.conf/etc/sysctl.conf_bak
2.vi /etc/sysctl.conf
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
net.ipv4.tcp_syncookies= 1
kernel.msgmnb= 65536
kernel.msgmax= 65536
kernel.shmmax= 68719476736
kernel.shmall= 4294967296
vm.overcommit_memory = 1
net.ipv4.tcp_tw_recycle= 1
net.ipv4.tcp_tw_reuse= 1
net.ipv4.tcp_fin_timeout= 1
net.ipv4.tcp_timestamps= 0
net.ipv4.tcp_synack_retries= 1
net.ipv4.tcp_syn_retries= 1
net.ipv4.tcp_keepalive_time= 600
net.ipv4.tcp_window_scaling= 1
net.ipv4.tcp_sack= 1
net.ipv4.tcp_max_syn_backlog= 600000
net.ipv4.tcp_max_orphans= 3276800
net.ipv4.tcp_mem= 786432 1048576 1572864
net.ipv4.tcp_rmem= 4096 87380 16777216
net.ipv4.tcp_wmem= 4096 65536 16777216
net.core.wmem_max= 16777216
net.core.wmem_default= 16777216
net.core.rmem_max= 16777216
net.core.rmem_default= 16777216
net.core.somaxconn= 262144
net.ipv4.tcp_max_tw_buckets= 1000000
net.core.netdev_max_backlog= 262144
vm.hugetlb_shm_group= 501
vm.nr_hugepages= 0
net.netfilter.nf_conntrack_max= 1048576
net.netfilter.nf_conntrack_tcp_timeout_time_wait= 10
vm.swappiness= 10
vm.zone_reclaim_mode=1
修改ulimit
1.vi /etc/security/limits.conf
* soft nproc 65535
* hard nproc 65535
* soft nofile 65535
* hard nofile 65535
2. vi /etc/security/limits.d/90-nproc.conf
* soft nproc 65535
记得重启服务器
