Installation on CentOS8 VirtualBox

What is written in this memo

• CentOS8 installation flow
• How to deal with the problem that the installation screen is cut off
• How to install VirtualBox Guest Additions
• How to disable IPv6: for sysctl
• How to disable IPv6: For kernel boot option

Installation conditions

Installation

1. Select Install CentOS Linux 8.0.1905 (Items 1 to 3 are failure examples. Start with Item 4)

2. Language selection (Items 1 to 3 are examples of failures. Start with Item 4)

3. Installation overview (Items 1 to 3 are examples of failure. Start from item 4) When I start the installer normally, the screen is cut off like this.

4. Start installation With Install CentOS Linux 8.0.1905 selected, press Tab to display the menu. Add vga = 773 to the end to start the installer.

• At this point, it is in English keyboard mode. For Japanese keyboard, press "^" to enter "=". Reference: GRUB VGA Modes

1. Language selection Select the language you want to use. I chose Japanese.

2. Installation overview Time and date Installation destination (disk and partition if necessary) Disable KDUMP (If you have a home server, even if you get KDUMP, it will not be analyzed, right?) Network and host name (Let's set the host name even with DHCP)

3. Select the time and date and select the region I chose Asia / Tokyo

4. Set the installation disk, partition if necessary I accepted the standard disc selection.

5. Disable KDUMP Uncheck Enable kdump If you need it, you can accept the standard settings without unchecking it.

6. Network and host name Host name setting Turn Ethernet on

7. Check the installation overview Click Start Installation

8. User settings Set the root password and create a general user account.

9. Set root password

10. Create user Specify the information of the user to create I'm working with the user I created here by checking "Make this user an administrator".

11. Reboot Wait for the installation to finish before rebooting. Don't forget to remove the installation media.

12. Accept the license

13. If you can confirm and agree to the license Check I accept the license.

14. Initial setup completed

15. Login

16. Settings for first login 1: Language selection

17. Setting at first login 2: Input method selection

18. Settings for first login 3: Privacy settings

19. Settings for first login 4: Connecting to an online account (optional, I'm skipping)

20. Settings for first login 5: Completed

VirtualBox Guest Additions installation

1. Add required packages Install the development environment for VirtualBox Guest Additions installation At first, the installation of VBoxGuestAdditions failed, so when I looked at setup.log, it requested the following module, so It is installed together with the development environment. libelf-dev lebelf-devel or elfutils-libelf-devel

   [user01@centos8 ~] sudo dnf group install -y "Development Tools"
   [user01@centos8 ~] sudo dnf install -y  elfutils-libelf-devel
   

2. Implementation of update In most cases, there will be a gap between the additionally installed kernel-header and the running kernel. Let's update and match the version of the package.

   [user01@centos8 ~] sudo dnf clean all
   [user01@centos8 ~] sudo dnf check-update
   [user01@centos8 ~] sudo dnf -y upgrade
   [user01@centos8 ~] sudo shutdown -r now
   

3. Installing VirtualBox Guest Additions 1 Guest Additions Select Insert CD Image

4. Install VirtualBox Guest Additions 2 When the VBox_GAs_XXX screen appears, click Execute. If the screen does not appear, execute the installation with the following command.

   [user01@centos8 ~] sudo /run/media/user01/Vbox_GAs_6.0.14/VBoxLinuxAdditions.run
   [user01@centos8 ~] sudo shutdown -r now
   

5. Install VirtualBox Guest Additions 3 If you are required to authenticate, please enter your credentials.

6. Install VirtualBox Guest Additions 4

When the installation is complete, restart the OS and you're done.

IPv6 disabled

Method 1: Disable with sysctl

1. IPv6 disabling settings in sysctl.conf

   [user01@cent8 ~]$ sudo vi /etc/sysctl.d/ipv6.conf
   net.ipv6.conf.all.disable_ipv6 = 1
   net.ipv6.conf.default.disable_ipv6 = 1
   [user01@cent8 ~]$ sudo sysctl --load /etc/sysctl.d/ipv6.conf
   

2. IPv6 disable setting in NetworkManager If you are using NetworkManager If you restart the OS or restart nic with a command, IPv6 will be enabled. Configure NetworkManager not to enable IPv6. (Replace enp0s3 with the NIC name of your server)

   [user01@cent8 ~]$ nmcli connection show enp0s3 |grep ipv6.method
   ipv6.method:                            auto
   [user01@cent8 ~]$ sudo nmcli connection modify enp0s3 ipv6.method ignore
   [user01@cent8 ~]$ nmcli connection show enp0s3 |grep ipv6.method
   ipv6.method:                            ignore
   [user01@cent8 ~]$ 
   

Method 2: Disable with Kernel Boot Option

1. Add "ipv6.disable = 1" to the end of the GRUB_CMDLINE_LINUX line.

   [user01@cent8 ~]$ sudo vi /etc/default/grub 
   GRUB_TIMEOUT=5
   GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
   GRUB_DEFAULT=saved
   GRUB_DISABLE_SUBMENU=true
   GRUB_TERMINAL_OUTPUT="console"
   GRUB_CMDLINE_LINUX="resume=/dev/mapper/cl-swap rd.lvm.lv=cl/root rd.lvm.lv=cl/swap rhgb quiet ipv6.disable=1"
   GRUB_DISABLE_RECOVERY="true"
   GRUB_ENABLE_BLSCFG=true
   [user01@cent8 ~]$ 
   

2. Reflect Grub settings Execute grub2-mkconfig by specifying the link destination confirmed by ls. If there are two links, also execute grub2-mkconfig twice.

   [user01@cent8 ~]$ ls -lh /etc/grub*.cfg
   lrwxrwxrwx.1 root root 22 October 3 02:01 /etc/grub2.cfg -> ../boot/grub2/grub.cfg
   [user01@cent8 ~]$ sudo grub2-mkconfig -o /boot/grub2/grub.cfg
   Generating grub configuration file ...
   done
   [user01@cent8 ~]$ 
   

Common setting

This setting is common regardless of whether IPv6 is stopped by either sysctl / kernel boot option.

1. Remove IPv6 entry from / etc / hosts Delete or comment out the IPv6 entry.

   [user01@cent8 ~]$ cat /etc/hosts
   127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
   ##::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
   [user01@cent8 ~]$ 
   

2. Remove the IPv6 entry from / etc / netconfig Suppress error messages. Delete or comment out the udp6 / tcp6 line.

   [user01@cent8 ~]$ sudo vi /etc/netconfig 
   #
   # The network configuration file. This file is currently only used in
   # conjunction with the TI-RPC code in the libtirpc library.
   #
   # Entries consist of:
   #
   #       <network_id> <semantics> <flags> <protofamily> <protoname> \
   #               <device> <nametoaddr_libs>
   #
   # The <device> and <nametoaddr_libs> fields are always empty in this
   # implementation.
   #
   udp        tpi_clts      v     inet     udp     -       -
   tcp        tpi_cots_ord  v     inet     tcp     -       -
   ##udp6       tpi_clts      v     inet6    udp     -       -
   ##tcp6       tpi_cots_ord  v     inet6    tcp     -       -
   rawip      tpi_raw       -     inet      -      -       -
   local      tpi_cots_ord  -     loopback  -      -       -
   unix       tpi_cots_ord  -     loopback  -      -       -
   [user01@cent8 ~]$ 
   

reference

• CentOS 8.0.1905 documentation
• Another way to eliminate screen breaks is to set the virtual machine's graphics controller to VBoxSVGA.