1, Installing virtual machines

1. This experiment is to package the master disk of RedHat 7.6 in the host of RedHat 8.2 and install multiple virtual machines

2. We need to prepare two images, one is rhel-server-7.6-x86_64-dvd.iso, one is rhel-8.2-x86_64-dvd.iso

3. Download location of image

We can visit red hat's official website to download the required images: Log In | Red Hat IDPhttps://access.redhat.com/downloads/content/479/ver=/rhel---8/8.2/x86_64/product-software

  4. Enter virt manager in superuser

        1) Click the little sun in the upper left corner to start creating the virtual machine

        2) Install the virtual machine in the order shown

        

 

Others choose the memory size and number of cores of the virtual machine according to the performance of their own computer

  

 

Select auto partition for disk partition  

Give superuser password

 

Create a normal user

  After the installation, just click reboot

2, Virtual machine master configuration

        1) Set IP

vi /etc/sysconfig/network-scripts/ifcfg-eth0
TYPE=Ethernet
BOOTPROTO=none
DEVICE=eth0
ONBOOT=yes
IPADDR=172.25.50.1
PREFIX=24
GATEWAY=172.25.50.250
DNS1=114.114.114.114

Then restart the network

nmcli connection reload
nmcli connection up System\ eth0

        2) Close firewall and relinux

systemctl disable --now firewalld

vi /etc/sysconfig/selinux
 Replace line 7 with SELINUX=disabled

Enter reboot to restart the virtual machine to make selinux settings take effect

         3) Build software warehouse

Real machine: image hanging on 7.6

mount /iso/rhel-server-7.6-x86_64-dvd.iso /var/www/html/rhel7.6/​

Photo editing machine software warehouse

vim /etc/yum.repos.d/dvd.repo
[dvd]
name=rhel7.6
baseurl=file:///var/www/html/rhel7.6
gpgcheck=0

Write virtual machine software warehouse  

vi /etc/yum.repos.d/dvd.repo
[dvd]
name=rhel7.6
baseurl=http://172.25.50.250/rhel7.6
gpgcheck=0

Test in real machine

Access in firefox browser 172.25.254.50/rhel7.6/

As shown in the figure, it is successful. If the content is not displayed, it indicates failure

Check whether the real apache service is normal

systemctl status httpd            see httpd Is the service enabled
###If not
systemctl enable --now httpd      start-up httpd And set it to startup
###If httpd is not downloaded
yum install -y httpd              download httpd
systemctl enable --now httpd      start-up httpd And set it to startup

        4) Configure the address resolution file in the virtual machine

 vim /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
172.25.50.250 foundation50.ilt.example.com
172.25.50.1 server1
172.25.50.2 server2
172.25.50.3 server3
172.25.50.4 server4
172.25.50.5 server5

Install the required software in the virtual machine

yum install -y vim lftp bash-* net-tools

Finally, shut down the virtual machine directly and enter poweroff

3, Encapsulate virtual machine

1) View virtual machine size

du -sh /var/lib/libvirt/images/small.qcow2
21G    /var/lib/libvirt/images/small.qcow2

2) Install the clean-up compression tool, clean up disk files, and compress the virtual machine small.qcow2 to small-new.qcow2

yum install libguests-tools.noarch libguestfs-tools-c.x86_64 -y		##Clean up compressed software
virt-sysprep -d base					##Clean up the disk files (note that. qcow2 suffix cannot be added here, only write the domain name)
which virt-sparsify						##The command to compress the original virtual machine. Find this command
rpm -qf /usr/bin/virt-sparsify			##Not installed
virt-sparsify --compress base.qcow2 base-new.qcow2					##Compress the original virtual machine to base-new.qcow2
du -sh base-new.qcow2					##Determine the size, usually only a few hundred megabytes

Looking at the size of the virtual machine again, you will find that

du -sh /var/lib/libvirt/images/small.qcow2
635M	/var/lib/libvirt/images/small.qcow2

Next, create a virtual machine snapshot

Steps:

Set the host name, IP address and check the network connection

qemu-img create -f qcow2 -b base-new.qcow2 server1    ##Create Snapshot 
qemu-img create -f qcow2 -b base-new.qcow2 server2
qemu-img create -f qcow2 -b base-new.qcow2 server3

Open virtual machine to view ip display

ip addr show eth0
inet 172.25.50.1/24 
###If not, the ip needs to be changed

View host name

hostname
server1
 Here and in front
/etc/hosts The host name and of the edit in ip Corresponding

  Repeat the operation to obtain multiple virtual machines

Package complete