This tutorial explains how to install RHEL Linux step by step. RHEL installation involves several options and configuration values that need to be set, adjust and configure. Learn each RHEL installation step and its option in detail with example to perform an error free RHEL Linux installation.
This tutorial explains RHEL 7 installation process from the first screen that we interact after booting system from RHEL installation media.
On First screen we have three options :-
Install Red Hat Enterprise Linux 7.2 :- Select this option to start installation process immediately.
Test this media & install Red Hat Enterprise Linux 7.2 :- Select this option to test the installation media before installation. Make sure you have sufficient time if selecting this option.
Troubleshooting:- Select this option for troubleshooting. This option contains four sub-options :-
Install Red Hat Enterprise Linux 7.2 in basic graphics mode :- Select this option to install RHEL 7.2 with generic graphic driver. If normal installation failed with black screen, restart the computer and try this option.
Rescue a Red Hat Enterprise Linux system :- Select this option to repair the existing RHEL system.
Run a memory test :- Select this option to run a memory test.
Boot from local drive :- Select this option if you have accidentally booted the system with this installation disk. This option will abort the installation process immediately and boot the system from hard disk.
Kernel Boot option :- By default this option is not listed here, to get this option we have to press the Tab key. Kernel boot option is used to access the minimum required OS environment for troubleshooting the existing operating system.
If we don’t select any option here, installation process will start automatically with the default option in 60 seconds. Default option is “Test this media & install Red Hat Enterprise Linux 7.2”.
Select first option to start the installation process. Hit Enter key to confirm the action.
Usually operating systems uses an installation program which performs all necessary tasks during the installation process with user permission and choice wherever applicable. RHEL uses Anaconda installer program for installation.
In a few seconds anaconda will load in memory. Once loaded, it will handle the installation process. The first information which anaconda needs is Language & Keyboard Setting that we want to use during the installation process.
This Language and Keyboard Setting will be used only for installation unless we keep the same Language and Keyboard Setting when Anaconda asks for Language and Keyboard Setting in next step.
If we change it there then that will be used RHEL after installation and this will be used for installation purpose only.
Select appropriate Language & Keyboard Setting for installation and click Continue.
Unlike other installer programs which require user input for configuration values in a pre-defined sequence, anaconda uses a single screen for most configuration values which can be configured in any order. Some values are automatically configured based on system hardware and installation media type. If requires, we can also change these pre-selected values. Until all necessary configuration values are configured, Continue button will not highlight.
We have seven different options here:-
- Date & Time
- Language Support
- Installation Source
- Software Selection
- Installation Destination
- Network & Hostname
Let’s configure above options one by one
Date & Time
This option allows us to set date, time, time zone and network time. To select time zone we have two options; either select from drop down box or click the time zone of our area in map.
If network card is configured and system is connected with Internet, we can use network time. This option will not work until we configure the network first.
Set the Date & Time and Time Zone and click Done.
This option is used for following purpose:-
- To change default Keyboard Layout
- To install multiple Keyboard Layout.
The screen is divided in two panes. Left pane is used to Add/ Remove Keyboard Layout while right pane is used to test the selected layout.
If we don’t change the Keyboard Layout in this option, default Keyboard Layout ( Layout that we have selected on welcome screen) will be used.
Select the appropriate Keyboard Layout and click Done.
This option is used to set the Language of RHEL. Just like Keyboard Layout, either we can keep the default Language (the language which we have selected on welcome screen) or select a new language for RHEL. If we want to use the same language then no change is required here. If we want to use the other language then select that and click Done.
RHEL can be installed from multiple sources. This option allows us to select the location of RHEL media.
Auto-detected installation media
If we have used RHEL installation disk to boot the system and want to use the same disk to install the RHEL then no option need to change here, just keep default setting. Correct source will be detected automatically. If needed, we can test installation media with Verify option. This option is the same option that we have seen on first screen (“Test this media & Install Red Hat Enterprise Linux 7.2” )
If we have used minimal boot environment to boot the system then we have to provide the location where RHEL installation disk is stored. Installer supports following locations:-
This option allows us to install RHEL from the IOS file that is stored locally. Since this option searches IOS file in local drives, it will be available only if installer program detect a partitioned hard drive with mountable file system. If you don’t see this option then its mean that hard disk does not contain any mountable file system. Either it is a blank hard disk or contains a file system which cannot be mounted.
On the network
This option allows us to install Linux from network. Usually network installation is used in companies where installation need to be perform on several computers. Suppose we have a single RHEL installation disk and need to install Linux on 100 computers. In this situation if we perform installation one by one on each system, it may take up to 3 days. Network installation reduces this time in hours.
Through network installation we can install Linux simultaneously on all computers. In Network installation we make a copy of RHEL installation disk on central location and access it on all computers. RHEL supports various network protocol to access the centralized installation media such as http, https, ftp and nfs.
Depending on our selection rest of options will be appear or disappear. For example if we select On the network with http:// (network protocol) then URL filed will be appear to provide the location of installation media.
If we want to install RHEL from auto detected installation disk then nothing need to be change here.
This option allows us to customize our installation. RHEL can be used on various platforms. Different platforms need different tools. For example a developers workstation requires web development tools such as C, C++, JAVA, PHP etc. While a Server system needs server tools such NFS Server, DNS Server, FTP Server etc. Tools are grouped in packages and organized into the Base environments.
A base environment is a set of pre-defined packages for a specific purpose; for example Basic Web Server environment contains a set of software packages which are usually requires to run a web server.
Each base environment can be further customized with additional Add-ons packages. We are allowed to select only one base environment.
If you are setting up this system for RHCE training or practice, select Server with GUI base environment.
Select the appropriate base environment and click Done.
This screen contains three options; disk option, partition option, encryption option.
Disk option (Compulsory)
This option is used to specify the location where we want to install the RHEL.
Local Standard Disks :- This option lists all detected local disks. To install RHEL on any of these disks, select that.
Specialized & Network Disks :- This option lists all network disks including any specialized disks such as raid array devices. To install RHEL on any of these disks, select that.
Add a disk :- If you don’t want to install RHEL on any available disk, use this option to install a new disk.
We must have to select at least one disk to install the RHEL.
If we select RAID device, we must have to create /boot partition separately outside the RAID array. We may use internal or local hard drive for this purpose.
Before installer can install RHEL in selected disk, it must be partitioned with Linux file system.
Partition Options (Compulsory)
We have two options for partitioning; automatic and manual.
Automatically configure partitioning
If we select this option, installer will create all necessary partition automatically on selected disk (in above option). This option accepts one more parameter.
I would like to make additional space available :- If we select this checkbox, installer will use only the specified disk space from available space. Remain disk space will be kept untouched. We can use remaining unallocated space in other operating system.
I Will Configure Partitioning
If we select this option, we have to create all necessary partitions manually. (Explained shortly)
We must have to select one partitioning option. There is no hard and fast rule about which option should you choose. If we select automatic partitioning, no further steps require in this option but if we select manual partitioning, we have to create necessary partition manually.
Encrypt my data (Optional)
This option is used to encrypt all partitions excepts /boot. Partitions are encrypted through the Linux Unified Key Setup utility. If we select this option, we have to provide a passphrase in next screen.
If you decided to use this option, make sure you keep passphrase safely. If you forget the passphrase, forget about the data stored in encrypted partition. There is no way to recover a lost passphrase. No trick, no method, no utility can help you to recover the encrypted data. Even if you have paid subscription from RHEL, support team will not be able to assist you on this matter.
If you are setting up this system for RHCE training or practice, use manual partition with following partitions layout.
- / (10 Gb)
- /boot (500 Mb)
- /home (1Gb)
- Swap (1Gb)
- Unallocated space (at least 2Gb)
Manual partitioning screen will appear only if we have selected I will configure partitioning in Installation Destination option. This screen allows us to configure disk partitions and mount points manually.
This screen is divided in two panes; left and right. Right pane shows the configuration options for selected partition from left pane. Left pane shows the existing partitions with partition management options; Add, Remove and Cancel. If installer program does not detect any existing partition then this pane would display only information about creating mount points. Total disk space and available space are displayed below the pane.
Minimum requirement for RHEL installation is only one partition / (root partition). But I suggest you to create at least four partitions.
This partition contains kernel and other necessary files which are required to boot the system. If we don’t create this partition separately then installer will automatically create this partition and mount with root partition. Keeping this partition with root partition has two issues
- If root partition is larger than 2TB then system will not be able to access /boot partition during the startup. To solve this issue, either keep root partition less than 2TB or mount /boot partition on a separate disk which has size less than 2 TB.
- If root partition is mounted in RAID array device then some BISO will not be able to access /boot partition during the startup. Again to solve this issue either mount entire root partition on a standard disk or mount /boot partition separately (on standard disk).
In both case first option is not suitable. But we can opt for second option easily. Having a separate /boot partition also makes troubleshooting easy. By creating a separate /boot partition, virtually we are limiting booting problem with in a partition.
Minimum recommended size for /boot partition is 500MB. Since it contains only booting files, any space more than 1Gb will be useless.
/ (Root partition)
This is the main and compulsory partition of any Linux system. This partition contains the top level directory in Linux file system. Linux starts with this directory. Unless we assign a separate mount point (such as /boot or /home)all files and directories will be written in this partition.
Minimum recommended size for this is partition is 5Gb. But I suggest you to allocate at least 10Gb for this partition. 10Gb is the sufficient size for most common packages.
Don’t confuse with /root directory which is the home directory of root user. / stand for root partition while /root stand for the home directory of the root user.
By default Linux stores users data in this partition. It is a common practice to keep user data separate from system data in work environment. This way we can upgrade or reinstall RHEL without touching user data.
Minimum recommended size for this partition is 1GB.
This partition works as virtual memory. System may use this virtual memory, if there is no enough space in RAM to process the data. Make sure we understand it correctly, it is not an actual RAM. It is only an additional hard disk space that can used as RAM to handle the extra load. To determine the extra load we have to look at the applications which will run on this system. Based on applications requirement we can adjust the size of swap space. If we are unsure about the applications which will run on this system, we may use following recommended size for swap space by Red Hat.
Recommended Swap Space by Red Hat
|Physical RAM||Recommended Swap Space||Recommended Swap Space if hibernation is used|
|Less than 2 GB||2 times of RAM||3 times of RAM|
|2GB to 8GB||Equal to RAM||2 times of RAM|
|8GB to 64 GB||0.5 time of RAM||1.5 times of RAM|
|More than 64GB||Workload dependent||hibernation not recommended|
Okay now we know the minimum recommended partition let’s create them one by one.
Click Add button, Select /boot from drop down, Allocate the size and click Add mount point.
/ (Root Partition)
Click again Add button and select / (root partition) from mount point drop down. Enter desire size of partition and click Add mount point. We can use standard size units such as kilobytes, megabytes, gigabytes, or terabytes. Megabytes is the default unit.
Repeat same process again and add swap partition.
Finally add home partition by following same steps.
If you want to correct any configuration, use right pane. As I mentioned earlier, right pane shows the configuration option for selected partition from left pane.
Mount Point :– The point, where this partition will attach with partition table.
Desired Capacity :– The size of partition. Default unit size is Mb.
Device type :– Contain the list of supportive device types. More options may appear or disappear based on selection.
File System :- File system of selected partition.
Label :- Label of selected partition. Labels are used to recognize the partition.
Name :- Name of selected partition. We are not allowed to change the name of standard partition such /home.
When you are finished Click Done button from upper left corner.
Before writing these change to disk, installer will present a summary of changes. If everything is fine, click Accept changes otherwise click Cancel & Return to custom partitioning.
Before RHEL 7.2 this option was available as add-on. From RHEL 7.2 this option is available on installation summary screen. It allows us to install RHEL under the several restriction and recommendation defined by Security Content Automation Protocol (SCAP) standard. Rules and recommendation are grouped in packages.
If you select any profile except the default, RHEL will be installed using the restrictions and recommendations defined in that profile.
In LAB environment we should use default profile which contain no rules.
Network & Hostname
This option allows us to configure hostname and NIC card. By default network card is disabled. Before configuration we have to enable it. Once enabled, it will obtain necessary configuration automatically from DHCP server. If there is no DHCP sever in network, we have to configure these setting manually.
Use Configure button to assign IP addresses and other values statically.
Left bottom corner has a text filed for host name. Default host name is localhost.localdomain.
After updating hostname and network configuration click Done.
Once we are done with all configuration options in installation summary screen click Begin Installation.
Once clicked, installation process will start immediately.
While installation process is going on, installer program will prompt us for setting up password for root user. Root is the default administrator account in Linux system. Click Root password
If we want to use a weak password, we have to click Done button twice. Using a weak password (such as 123456 or ABCDEFG) is common in LAB environment. But it is strongly recommended, never use such a weak password in production environment.
Next click User Setting and create a normal user account. A normal user account need three values:-
- Full Name :- Name of user
- User Name :- User name of user
- Password :- Password for user account
We can also configure advance options (such as home directory, login option) but they are not necessary at this moment.
Now wait till installer finish the first part of installation. A system reboot is required to launch the second and final part of installation.
After rebooting final part of installation will begin. It contains only two steps; Accept the license agreement and register the system with Red Hat network.
Once we accept the license Finish Configuration button will be highlighted, click it to access the graphical login prompt. Login with the user account that we have created during the installation.
Since we logging in graphic mode first time, Gnome will present initial setup wizard.
Select Keyboard Layout
If system is connected with internet, gnome will prompt you to connect with your online accounts. Skip it.
That’s all information gnome needs. Click Start using Red Hat Enterprise Linux Server.
We have successfully install RHEL 7.2.
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