查看cpu
[root@llpt7 ~]# cat /proc/cpuinfo | grep name | cut -f2 -d: | uniq -c
12 Intel(R) Xeon(R) cpu E5-2620 v3 @ 2.40GHz
12核
[root@llpt7 ~]# getconf LONG_BIT
64
当前cpu运行在64位下
2.查看内存
[mushme@investide ~]$ free -mh
重点：记录CentOS 7与以往不同的地方
1.取消ifconfig，使用ip addr 或者 ipa a 查看IP地址。
2. 安装 ifconfig 和 nslookup: yum install net-tools, yum install bind-utils, nslookup,dig在bind-utils中
3.使用firewalld 取代 iptables。
4.系统默认编码设置文件，由/etc/sysconfig/i18n 更改为 /etc/locale.conf
1. How to configure a static IP address on CentOS 7
http://ask.xmodulo.com/configure-static-ip-address-centos7.html
2. Linux有问必答：如何为CentOS 7配置静态IP地址
https://linux.cn/article-3977-1.html
1. To verify the status of Network Manager service:
systemctl status NetworkManager.service
2. To check which network interface is managed by Network Manager, run:
nmcli dev status
3.不使用网络管理配置静态IP地址, 可以直接修改 /etc/sysconfig/network-scripts/ifcfg-enp0s3 文件，然后执行
systemctl restart network.service 或者 service network restart
IPADDR=192.168.56.40
PREFIX=24
NM_CONTROLLED=no
HWADDR=08:00:27:4F:B6:68
TYPE=Ethernet
BOOTPROTO=none
NM_CONTROLLED=no
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME="Wired connection 1"
UUID=221c3c3a-5e15-3f05-9bdf-869eae33129f
ONBOOT=yes
AUTOCONNECT_PRIORITY=-999
IPADDR=192.168.56.40
PREFIX=24
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes
请切记不能写GATEWAY在ifcfg文件中。
“NM_CONTROLLED=no”表示该接口将通过该配置文件进行设置，而不是通过网络管理器进行管理。“ONBOOT=yes”告诉我们，系统将在启动时开启该接口。
4. dns在 vi /etc/resolv.conf中配置：
[root@mouse ~]# cat /etc/resolv.conf
# Generated by NetworkManager
nameserver 8.8.8.8
nameserver 8.8.4.4
nameserver 202.96.134.133
====================================
检查安全补丁centos6.x, centos7.x
yum --security upgrade
查询某个命令属于哪个安装包？ 例如查询 lsb_release
yum provides */lsb_release
yum whatprovides lsb_release
Centos/Linux下如何查看网关地址/Gateway地址
2015-09-10 16:49 5248人阅读 评论(0) 收藏 举报
Centos/Linux下如何查看网关地址/Gateway地址？ Linux下查看网关的命令还是很多的，不过如果IP是DHCP获取，那么有些命令是不适用的，当然也有通用的查询网关命令.
1.ifconfig -a 和 cat /etc/resolv.conf （主要查看ip/netmask和dns）
2.netstat -rn
3.cat /etc/sysconfig/network
4.cat /etc/sysconfig/network-scripts/ifcfg-eth0
5.traceroute 第一行就是自己的网关
6.ip route show
7.route -n
===
B - CentOS 6
yum -y install wget lrzsz
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
wget -O /etc/yum.repos.d/CentOS-Base-163.repo http://mirrors.163.com/.help/CentOS6-Base-163.repo
yum clean all
yum makecache
yum install vim* 测试是否源可用
yum update -y
yum --releasever=6.6 update -y
6、reboot
7、查看系统类型cat /etc/redhat-*（忘记*是啥了，直接Tab键即可）
回退到上个小版本Downgrade the the redhat-release package to complete the process. The command below targets the latest minor version that is lower than the current running one, such as from 6.5 to 6.4, or from 6.4 o 6.3:
yum downgrade redhat-release
cat /etc/redhat-release
