Howto do a netinstall of Ubuntu 16.04 LTS – minimal server installation

Minimal net install is useful when a dedicated server is installed from a IPMI KVM or Dell iDRAC, HP iLO, IBM IMM or where the initial download of files need to be minimal.

STEP 1) To do a Ubuntu net install first download the correct ISO file from Ubuntu site.

For amd64 Ubuntu 16.04 the net install bootable media is located here (the netboot image is required):

http://archive.ubuntu.com/ubuntu/dists/xenial-updates/main/installer-amd64/current/images/netboot/

Download “mini.iso”:

http://archive.ubuntu.com/ubuntu/dists/xenial-updates/main/installer-amd64/current/images/netboot/mini.iso

The ISO is just only 62Mbytes, so when installing from a remote management utility (some of the different IPMI KVMs) only 62Mbytes will be transferred from the client to the server and all other packets will be downloaded from the Ubuntu mirrors.

STEP 2) Select “Install” and press Enter to select installation and to continue.

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Installer boot menu

STEP 3) Select your preferred language for the installation steps, this tutorial use English, so probably it is a good idea to just select “English”.

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Select a language

STEP 4) Select the location of your machine you are installing. The default is “United States”.

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Select your location

STEP 5) Autodetect your keyboard layout is skipped (the next step is for manual choosing the keyboard layout), just press “No”.

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Configure the keyboard

STEP 6) Select the country of origin for the keyboard your are using.

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Configure the keyboard 2

STEP 7) Select your keyboard layout – most used is “English (US)”, but if your keyboard is in different language you could select it from the menu. And then press Enter.

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Configure the keyboard 3

STEP 8) You’ll see a couple of dialogs about the network setup, press immediately Cancel (the Cancel is the default, so just press couple of times “Enter”) to cancel the DHCP setup of the network. When installing a dedicated server you must have the IP from your provider of the service. When installing at home probably you could just leave it without pressing “Cancel” and your home router will configure the IP of your machine. Here we describe the manual process of setting the network.

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Configure the network

STEP 9) After canceling the default process of network setup, there will be showed “Network configuration failed.”. Press “Enter” to continue with manual network configuration.

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Configure the network 2

STEP 10) Mark “Configure network manually” and press “Enter”.

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Configure the network 3

STEP 11) Set your IP address, the IP address of our dedicated server is 192.168.0.100 And press “tab” to mark “Continue” and then press “Enter”.

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Configure the network – The IP address

STEP 12) Set your netmask of the network. Here we set up the whole subnetwork /24, so the netmask is 255.255.255.0 And press “tab” to mark “Continue” and then press “Enter”.

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Configure the network – The netmask of your network.

STEP 13) Set the gateway of the network, the router IP (from where the Internet “comes”). Our router has IP 192.168.0.1 And press “tab” to mark “Continue” and then press “Enter”.

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Configure the network – The gateway

STEP 14) Set the nameservers to be used for resolving domain names to IP addresses, probably this is the IP of your router (as in our case), but you could use for example google DNS servers “8.8.8.8,8.8.4.4”. If you have more than one,just use commas to separate the IP addresses.

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Configure the network – The Name server address

STEP 15) Set the hostname of your server, this is the name of your machine. We use “ubuntu-test”. Or you can use more meaningful name like “srv1-dns-eu”

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Configure the network – The hostname

STEP 16) The domain name part of the server’s name if any. Leave blank or if you have it will be sort of “cdn.com”,so the fully qualified domain name (FQDN) will be “srv1-dns-eu.cdn.com”

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Configure the network – The full domain name

STEP 17) Select the source of the installation files and packages. Choose the nearest location to your machine to be sure the fastest speed and fast installation.

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Choose a mirror of the Ubuntu archive

STEP 18) The installation process will offer the right name of the mirror servers, select it and press “Enter”.

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Choose a mirror of the Ubuntu archive 2

STEP 19) If you need a proxy to connect to the Internet it is time to set it up, but probably you do not need it, so leave blank, press “tab” to mark “Continue” and press “Enter”

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Choose a mirror of the Ubuntu archive 3

STEP 20) …

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Setup is now working…

STEP 21) You must create a user account, which will have the ability to escalate to root, default process of installation do not allow to set root password, but a user, which could switch to root. Set the Full name of your user (it could be just the username as shown). And press “tab” to mark “Continue” and then press “Enter”.

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Set up users and passwords

STEP 22) Set the username, how you log in the system. We used the same as the Fullname from the previous step. And press “tab” to mark “Continue” and then press “Enter”.

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Set up users and passwords – username

STEP 23) Set the password of the user. And press “tab” to mark “Continue” and then press “Enter”.

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Set up users and passwords – password

STEP 24) Repeate the password of the user to verify you have typed it correctly. And press “tab” to mark “Continue” and then press “Enter”.

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Set up users and passwords – repeate password

STEP 25) If you would like you can encrypt your home directory. Most cases for servers, mark the default “No”, but for laptop or home desktop machine it it advisable to encrypt your personal data! So mark your choice and press “Enter”.

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Set up users and passwords – home directory encryption

STEP 26) Set the right timezone of your machine, most time for servers it is UTC and for leave it as detected. Press “Enter”.

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Configure the clock

STEP 27) Detecting disks configuration.

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Setup is now working…

STEP 28) The easiest way here is to use the entire disk for Ubuntu installation. All other options are for another tutorial, which could get more complicated. That’s why we use “Guided – use entire disk” for simplicity. It could be used LVM or encrypted LVM, too. Here we chose the simplest option.

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Partition disks

STEP 29) Select the disk to use for your ubuntu installation, if you have multiple disk be sure to select the right one! Choosing a wrong disk could lead to data loss. Press “Enter” to continue.

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Partition disks – select disk device

STEP 30) The user must confirm the changes on the disk, as it is written this operation will erased all the information ot your selected disk!!! Be sure you marked “Yes” and press “Enter”.

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Partition disks – confirmation

STEP 31) Installing the base system.

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Setup is now working…

STEP 32) Just select “No automatic updates” and hit “Enter”. Always update your system when you are online, becuase sometimes during update process there are service restarts, which could be critical for your server. So guided updates are always the right way!

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Configuring console-setup

STEP 33) Select and install software.

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Setup is now working…

STEP 34) What kind of system do you build? GUI, server or with specific services? These are predefined collections ensuring to install the right packages for the coresponding software collection.

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Software selection

STEP 35) We selected only OpenSSH server and Basic Ubuntu server, because we want to install a base linux system with remote access. Press “tab” and mark “Continue”, the press “Enter”.

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Software selection 2

STEP 36) Select and install software.

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Setup is now working…

STEP 37) Installing GRUB boot loader.

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Setup is now working…

STEP 38) Because this will be the only operating system, it is safe to install the GRUB to the master boot record. Mark “Yes” an hit “Enter”

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Install the GRUB boot loader on a hard disk

STEP 39) In most cases the system clock is set to UTC, so just press “Enter”. No problem to change this settings your case is not the same.

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Finish the Installation

STEP 40) Remove the installation disk – CD, DVD, unmap virtual CD/DVD or USB and then press “Continue”. The machine will restart.

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Finish the Installation 2

STEP 41) Ubuntu 16.04 is booting…

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Booting…

STEP 42) The machine is working properly, it is logged with myuser.

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Login

STEP 43) And here are the running programs of a base Ubuntu system.

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Running software

Howto do a netinstall of CentOS 7 (7.4.1708) – minimal server installation

Minimal net install is useful when a dedicated server is installed from a IPMI KVM or Dell iDRAC, HP iLO, IBM IMM or where the initial client side download of files need to be minimal.
For amd64 CentOS 7 the net install bootable media is located here (now the current latest release is 7.4.1708, but you can check the last directory with 7. for the time you follow this howto):

http://mirror.leaseweb.com/centos/7.4.1708/isos/x86_64/CentOS-7-x86_64-NetInstall-1708.iso

Now this version is deprecated and you could have problems downloading it, so you could try the CentOS vault – http://vault.centos.org/7.4.1708/isos/x86_64/ Just follow the instructions for downloading.
Download it and put it on a cd or usb, the boot from it and follow the steps bellow:

STEP 1) Select “Install CentOS 7” and press “Enter”

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Select CentOS 7 Installation

STEP 2) Wait for the installation to boot

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Booting the installation

STEP 3) This is the first step, you could choose your Country and language, English is the default.

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Country and language selection

STEP 4) Setup the right time and time zone of your server, this step is important, the clock of the server is really important for your software to work properly!

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Date & Time

STEP 5) Often servers are set with UTC time, which is never changed (no summer saving time!). UTC is Coordinated Universal Time and first you must select “Etc” from the first dropdown menu.

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Date & Time – UTC selected

STEP 6) Next let’s configure the network, because we are doing a network installation you need Internet connection to install the CentOS 7.

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Network & Host Name

STEP 7) Click to configure the selected network adapter on the right.

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Configure network Adapter

STEP 8) Click on the menu “IPv4 Settings”, then choose from the dropdown menu “Manual” (technically you can leave it Automattically as the default is, but this is a server howto it is not very clever your IP to be assigned by a DHCP server, but your setup could vary). Then click on “Add” and write your IP address, network mask and gateway, then in the DNS Servers write your local (and fast!) DNS server, if you have more than one separate them with comas.

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IPv Settings

STEP 9) Click “General” menu and then check the “Automatically connect to this network when it is available” – this is very important, because if you do not check, when you reboot the server, it won’t start the network! Click Save.

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General Adapter settings

STEP 10) You can see the network is up and connected. Set a host name to your server and click on “Apply” and that’s all for the network configuration, click on “Done”.

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Host Name setup

STEP 11) Click on “Installation Source” to setup the source of your installation files, because this is network installation this step is mandatory.

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Installation Destination

STEP 12) Set the URL from where the setup will download packages and installation files. Set the nearest source to your server, you can check mirrors here:

https://www.centos.org/download/mirrors/

At present the latest version of CentOS 7 is 7.4.1708, but after a while it could be other, so browse the latest version directory, then you must choose directory “/os/” (there are probably many others, but we need especially “os”) and then “/x86_64/”. And then click on “Done”. That’s all you’ve configured the installation source, so now the setup knows where to look for packages and metadata for the installation process.

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URL of the OS packages.

STEP 13) Choose your software to install. Click on “Software Selection”.

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Software Selection

STEP 14) Because this howto is a minimal installation you should check “Minimal Install” , but you could choose another option below, the one suited best for your future server. And then click on “Done” to save the configuration.

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Minimal Install

STEP 15) Click on “Installation Destination” to set the hard drive and partitions layout configuration for your server.

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Installation Destination

STEP 16) The default is to leave the how disk to the setup to manage (make sure the “Automatically configure partitioning.” is checked), it will use the how hard drive checked from the Local Standard Disks. Check all the local disks you want to use in your server if more than one. If your disk has partitions you may be prompted to acquire free space by deleting existing partitions – be careful with this option, think twice before deleting partitions! Click on “Done” to save configuration.

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Device selection – hard disk and partition configuration

STEP 17) Click on “Security policy” to setup a default security policy as selinux – use it whenever it is available!

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Security Policy

STEP 18) Click on the “Standard System Security Porfile”, which will enable SELINUX security in your installation and then click “Select Profile”, after clicking the button will become grayed and the selection will have a green check in the right. Then click on “Done”.

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Standard System Security Profile – SELINUX

STEP 19) We are all done and it is time to start the real installation of the system. Till now we’ve just configured the installation process. So click on “Begin Installation”.

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Begin Installation

STEP 20) When the installation process is running you are prompt to set the root password and to add users. For clarity we set only the root password.

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Root password setup

STEP 21) Set two times your password for the root user and then click “Done”.

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Enter root password

STEP 22) The installation process is still running, just wait to finish.

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Starting package installation process

STEP 23) You can see how many packets are install and the current installing packet and number.

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Installing packages…

STEP 24) If everything goes with no errors and probably it will be with no errors you must click on “Reboot” to reboot the server in the newly installed OS.

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Installation ready. Reboot

STEP 25) Grub2 and two options to select, the default is the latest kernel installed.

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Grub2, default kernel boot

STEP 26) And the server is at login. The ssh server is also installed and you can access the server via ssh on the default port 22 and root login is permitted.

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Login