一、设置安装系统内存及CPU大小
1、设置内存、CPU和硬盘大小
1、设置内存及CPU大小，创建新的虚拟机，设置一个100G硬盘，够用即可。
2、开始安装，安装过程将网卡名称改为eth0
1、传递内核参数 net.ifnames=0 biosdevname=0 以 更改 网卡名称为 eth0 ethX；
出现安装界面时使用键盘上下键 移动 到第一行即 Install Centos Linux 7 然后按 tab 键，即
可出现 传递 参数界面。
2、选择语言时，选择中文简体和英文，避免在英文界面上存在一些中文字体的出现乱码，并创建分区。
3、选择最小化安装
等待安装完成！！！
二、配置centos7的日常默认选项
1、开始配置centos7日常默认选项
1、安装最小化的命令
yum install vim iotop bc gcc gcc-c++ glibc glibc-devel pcre pcre-devel openssl \ openssl-devel zip unzip zlib-devel net-tools lrzsz tree ntpdate telnet lsof tcpdump \ wget libevent libevent-devel bc systemd-devel bash-completion traceroute bridge-utils -y
2、关闭防火墙，并设置为开机不启动
[root@openstack network-scripts]# systemctl stop firewalld [root@openstack network-scripts]# systemctl disable firewalld
3、关闭NetworkManager网络，避免影响网络不通，或者网卡启动不成功等问题
[root@openstack network-scripts]# systemctl stop NetworkManager [root@openstack network-scripts]# systemctl disable NetworkManager
4、关闭selinux配置文件
[root@openstack network-scripts]# cat /etc/sysconfig/selinux # This file controls the state of SELinux on the system. # SELINUX= can take one of these three values: # enforcing - SELinux security policy is enforced. # permissive - SELinux prints warnings instead of enforcing. # disabled - No SELinux policy is loaded. SELINUX=disabled # SELINUXTYPE= can take one of three values: # targeted - Targeted processes are protected, # minimum - Modification of targeted policy. Only selected processes are protected. # mls - Multi Level Security protection. SELINUXTYPE=targeted
5、配置内核参数优化
[root@openstack network-scripts]# cat /etc/sysctl.conf # Controls source route verification net.ipv4.conf.default.rp_filter = 1 net.ipv4.ip_nonlocal_bind = 1 net.ipv4.ip_forward = 1 # Do not accept source routing net.ipv4.conf.default.accept_source_route = 0 # Controls the System Request debugging functionality of the kernel kernel.sysrq = 0 # Controls whether core dumps will append the PID to the core filename. # Useful for debugging multi-threaded applications. kernel.core_uses_pid = 1 # Controls the use of TCP syncookies net.ipv4.tcp_syncookies = 1 # Disable netfilter on bridges. net.bridge.bridge-nf-call-ip6tables = 0 net.bridge.bridge-nf-call-iptables = 0 net.bridge.bridge-nf-call-arptables = 0 # Controls the default maxmimum size of a mesage queue kernel.msgmnb = 65536 # # Controls the maximum size of a message, in bytes kernel.msgmax = 65536 # Controls the maximum shared segment size, in bytes kernel.shmmax = 68719476736 # # Controls the maximum number of shared memory segments, in pages kernel.shmall = 4294967296 # TCP kernel paramater net.ipv4.tcp_mem = 786432 1048576 1572864 net.ipv4.tcp_rmem = 4096 87380 4194304 net.ipv4.tcp_wmem = 4096 16384 4194304 net.ipv4.tcp_window_scaling = 1 net.ipv4.tcp_sack = 1 # socket buffer 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 = 262144 net.core.somaxconn = 20480 net.core.optmem_max = 81920 # TCP conn net.ipv4.tcp_max_syn_backlog = 262144 net.ipv4.tcp_syn_retries = 3 net.ipv4.tcp_retries1 = 3 net.ipv4.tcp_retries2 = 15 # tcp conn reuse net.ipv4.tcp_tw_reuse = 1 net.ipv4.tcp_tw_recycle = 1 net.ipv4.tcp_fin_timeout = 1 net.ipv4.tcp_max_tw_buckets = 20000 net.ipv4.tcp_max_orphans = 3276800 net.ipv4.tcp_timestamps = 1 #? net.ipv4.tcp_synack_retries = 1 net.ipv4.tcp_syncookies = 1 # keepalive conn net.ipv4.tcp_keepalive_time = 300 net.ipv4.tcp_keepalive_intvl = 30 net.ipv4.tcp_keepalive_probes = 3 net.ipv4.ip_local_port_range = 10001 65000 # swap vm.overcommit_memory = 0 vm.swappiness = 10 #net.ipv4.conf.eth1.rp_filter = 0 #net.ipv4.conf.lo.arp_ignore = 1 #net.ipv4.conf.lo.arp_announce = 2 #net.ipv4.conf.all.arp_ignore = 1 #net.ipv4.conf.all.arp_announce = 2
6、配置文件大小限制
[root@openstack network-scripts]# cat /etc/security/limits.conf #上面省略，以下是重要部分 * soft core unlimited * hard core unlimited * soft nproc 1000000 * hard nproc 1000000 * soft nofile 1000000 * hard nofile 1000000 * soft memlock 32000 * hard memlock 32000 * soft msgqueue 8192000 * hard msgqueue 8192000
7、poweroff关机，保存快照，系统安装完成，设置也完成，此时centos7整个基本配置完成，就可以放到生产中使用了。