centos服務器安裝配置
一、安裝系統完畢後關閉以下服務
1、firewall和configuration-disable
2、sysytem services 保留：crond、network、sshd
二、新建賬戶，並設置允許新賬戶能sudo到root，禁止root賬戶ssh遠程登陸
#useradd lswang
#passwd lswang
#chmod 777 /etc/sudoers
#vim /etc/sudoers
查找/root yyp 修改lswang
#chmod 440 /etc/sudoers
#vim /etc/ssh/sshd_config
查找/#PermitRootLogin 去掉#，改yes爲no
#/etc/init.d/sshd restart
三、Web服務器裝機優化步驟
1、打開/etc/security/limits.conf文件，在End of file上面加上兩句 （打開最大文件連接數）
* soft nofile 51200
* hard nofile 51200
net.ipv4.tcp_max_syn_backlog = 65536
net.core.netdev_max_backlog = 32768
net.core.somaxconn = 32768
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_synack_retries = 2
net.ipv4.tcp_syn_retries = 2
net.ipv4.tcp_tw_recycle = 1
#net.ipv4.tcp_tw_len = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_mem = 94500000 915000000 927000000
net.ipv4.tcp_max_orphans = 3276800
net.ipv4.tcp_fin_timeout = 30
net.ipv4.tcp_keepalive_time = 120
net.ipv4.ip_local_port_range = 1024 65535
2、打開/etc/sysctl.conf文件，在最後邊插入如下語句：（優化內核）
kernel.shmall = 268435456net.ipv4.tcp_max_syn_backlog = 65536
net.core.netdev_max_backlog = 32768
net.core.somaxconn = 32768
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_synack_retries = 2
net.ipv4.tcp_syn_retries = 2
net.ipv4.tcp_tw_recycle = 1
#net.ipv4.tcp_tw_len = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_mem = 94500000 915000000 927000000
net.ipv4.tcp_max_orphans = 3276800
net.ipv4.tcp_fin_timeout = 30
net.ipv4.tcp_keepalive_time = 120
net.ipv4.ip_local_port_range = 1024 65535
然後執行以下命令使配置生效：
#/sbin/sysctl -p