RHEL 7/Centos 7 Installation

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External

Internal

Overview

This installation procedure has been tested on bare metal (ThinkPad laptops) and on VirtualBox VMs. The sections that refer to non-virtualized installation are prefixed with Bare Metal and indented. The sections that refer to virtualized installation are prefixed with VirtualBox and indented.

DVD

Download the RHEL 7.2 Binary ISO DVD from https://access.redhat.com.

Procedure

Boot with the Image DVD

Install Red Hat Enterprise Linux 7.2
...
Starting installer, one moment.

Welcome to Red Hat Enterprise Linux 7.2

What language would you like to use during the installation process? English -> English (United States) -> Continue

Installation Summary

First go to "Network & Host Name" to set external access.

Network & Host Name

Turn wireless off.

Virtual Box

If the hardware configuration was done according to the VirtualBox Linux VM Creation procedure, the NAT adapter is eth1. Turn it "ON" (upper right "button"). This is the VirtualBox NAT network interface, so it should get an IP address from its DHCP server and allow immediate external connectivity during the installation. The interface should show "Connected", get a valid IP address (example IP address 10.0.3.15, default route 10.0.3.2, DNS: a valid DNS or your local router). Then go to eth0 and turn it ON.

Bare Metal

Turn ethernet (enp0s25) ON.

Main Network Interface - Common Configuration Procedure

"Configure..."

General

Automatically connect to this network when it is available.

All users may connect to this network.

Ethernet

Device: eth0/enp0s25

MTU: automatic

IPv4 Settings

Method: Manual

Addresses: Add

Virtual Box

Address 172.20.2.11, Netmask 255.255.0.0, Gateway: leave empty. If you plan to use previously created VMs from the same subnet at the same time, pick IP addresses that do not overlap. TODO - does it have to be in the same subnet as the host-only network defined earlier?. Make sure to Save.

Bare Metal

Address 192.168.1.8, Netmask 255.255.255.0, Gateway: 192.168.1.1, DNS servers: 192.168.1.1

Make sure you Save.

Host Name

DO NOT FORGET

Go to "Host name".

Virtual Box

Specify the local host name: openshift-master1. If you are planning to use a local DNS server, specify openshift-master1.openshift.local

Bare Metal

now510.local

Done.

Date & Time

Time Zone.

Network Time: ON

Done.

Keyboard

English(US)

Installation Source

Local media

Software Selection

Minimal Install

Installation Destination

Virtual Box

Select the ATA VBOX HARDDISK. You may go for "Automatically configure partitioning" or if you don't want a root and a home partition, choose "I will configure partitioning" and go to Manual Partitioning.

Bare Metal

If the disk was previously partitioned and want to delete the previous partitions: Partitioning -> Automatically configure partitioning, check "I would like to make additional space available" -> Delete All -> Reclaim Space. If you don't want a root and a home partition, choose "I will configure partitioning" and go to Manual Partitioning.

Done.

The top level menu should show Automatic partitioning selected.

Manual Partitioning

"Click here to create them automatically". This will give a reasonable starting point.

Make sure new mount points will use the following partitioning scheme: LVM.

Simplest configuration:

  • "/boot", capacity 500 MiB, device type: Standard Partition, file system "xfs"
  • "/", capacity 3140 MiB, device type: LVM, file system xfs, volume group: rhel_lb, name: root
  • swap, capacity 409.6 MiB, device type: LVM, file system swap, volume group: rhel_lb, name: swap

Done

Kdump

Disable.

Begin Installation

Begin Installation

User Settings

Root password.

Create users as necessary, depending on the purpose of the box (openshift, wiki, etc)

You may also want create a service user with same name as the machine's.

If you create a service user, go to Advanced and add it to its own group.

Capture credentials in the standard location (Contacts for the host in question).

Reboot

Will eject the DVD by itself.

After reboot, the host should be available for ssh.

Post-Install Tasks

Enable Network Interfaced to Start at Boot

Sometimes the NAT network interface comes disabled at boot. Set ONBOOT=yes in /etc/sysconfig/network-scripts/ifcfg-eth1.

Register with the Subscription Manager

If this is a supported RHEL system, register it with the subscription manager, this will give access to official repositories for update. Instructions are available here: RHEL Subscription Manager#Register_a_Linux_System

Update All Installed Packages

yum update

Install Packages I Need

yum -y install wget unzip

policycoreutils-python is needed for semanage. See selinux#Configuration 

yum -y install policycoreutils-python

Configuration

Resolve the Host Name in /etc/hosts

Execute 

hostname

and update the host name in /etc/hosts to the main interface of the host. 

192.168.1.8 now510 now510.local

Disable the Network Manager

Linux 7 Configuring Network Manager#Disable_the_Network_Manager

Turn off firewalld and configure the iptables service

Optionally, add additional IPv4 firewall rules depending on the purpose of the host:

  1. Allow ssh access only from the internal network on a non-standard port (note this procedure implies reconfiguring the sshd server at the same time, otherwise we may lose remote access).
  2. iptables Command Line Tool Examples#Allow_a_Web_Server_on_a_Specific_Interface

If IPv6 is not explicitly configured and used, best if you block IPv6 access in firewall:

For a discussion on iptables service and firewalld, see iptables Concepts.

Turn off ssh DNS Resolution

Linux 7 Configuring Network Manager#Disable_the_Network_Manage

Configure DNS

bind Operations#Set_Up_DNS_on_a_Newly_Installed_Linux_System

Prevent the Computer to Go to Sleep when the Lid is Closed

How to Prevent the Computer to Go to Sleep when the Lid is Closed

Security Hardening

Linux 7 Security Hardening

Reboot

Reboot one more time, to make sure the system starts after patching and configuration: 

init 0

Bare Metal

Start the system from the power button.

VirtualBox

Start the system from the VirtualBox console.

Next Steps

VirtualBox

Continue VirtualBox Installation. If installing in VirtualBox, go back to the VirtualBox installation procedure https://home.feodorov.com:9443/wiki/Wiki.jsp?page=VirtualBoxVMCreation#GuestAdditions

Troubleshooting

VirtualBox - Failure to Boot with the Default Kernel

Did not know what I did, but I set storage as follows:

Controller IDE -> Empty -> IDE Primary Slave, No Live CD/DVD.

Controller SATA -> Port Count: 2 

*.vdi -> Hard Disk SATA Port 0, No Solid-state Drive.

A Network Adapter Does Not Start

Linux 7 Network Configuration#Network_Adapter_Does_Not_Start_After_Installation
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