System reinstallation and system performance query

Unable to find the image when reinstalling the system

stay centos7 Initial installation interface Press down tab key ,
Make the following modifications
The original content was ：vmlinuz initrd=initrd.img inst.stage2=hd:LABEL=CentOS 7 x86_64 rd.live.check quiet
Change the above content to the following
vmlinuz initrd=initrd.img dd linux quiet Then press enter , After a while, all hard disk information will be displayed .
to glance at U Which disk does the disk belong to? For example, the first column is sdb4
Then restart and re-enter Again tab modify
vmlinuz initrd=initrd.img inst.stage2=hd:/dev/sdb4 quiet 
Carriage return installation

configure network

BOOTPROTO="static"
DNS1=8.8.8.
DNS2=202.118.176.2
ONBOOT="yes"
IPADDR=192.168.101.(11-20)  first line 
PREFIX=16
GATEWAY=192.168.101.1
IPV6_PEERDNS=yes
IPV6_PEEROUTES=yes

Configure key

 The key configuration 
ssh-keygen   All return 
cd .ssh   Get into .shh Catalog 
cat id_rsa.pub >> authorized_keys   Install public key 
chmod 600 authorized_keys
chmod 700 ~/.ssh
vi /etc/ssh/sshd_config  Edit profile 
 Modify the following four lines , If the first line is blank, you can leave it blank 
RSAAuthentication yes
PubkeyAuthentication yes
PermitRootLogin yes
PasswordAuthentication no   # No password login 
 restart ssh
systemctl restart sshd.service
 Check the status 
systemctl status sshd.service
 Copy key 
cp id_rsa /root/Downloads/ip Count 

Query performance

cpu Number 
cat /proc/cpuinfo| grep "physical id"| sort| uniq| wc -l 
cpu Check the number 
cat /proc/cpuinfo | grep "cpu cores" | uniq
cpu model 
cat /proc/cpuinfo | grep 'model name' |uniq
 Check the hard disk size 
fdisk -l | grep Disk
 Look at the memory 
free -h

Firewall configuration

systemctl status firewalld
firewall-cmd --zone=public --add-port=22/tcp --permanent
firewall-cmd --reload
firewall-cmd --list-ports View allowed ports