Knowledge Base

Hetzner is known for its powerful infrastructure and competitive prices. On dedicated servers, even without KVM access, it is possible to install an operating system using ISO files via Rescue Mode. This article provides a comprehensive guide on how to perform ISO installation without KVM access using Hetzner Rescue Mode. This process is particularly useful when you want to install a new operating system, recover an existing system, or apply a custom configuration.

1. Introduction

Hetzner Rescue Mode is a special environment used to boot your server when there is no operating system on your server or the existing operating system is inaccessible. This mode comes with basic tools and network connectivity, allowing you to repair your server, recover data, or install a new operating system. KVM (Keyboard, Video, Mouse) access is a virtualization technology that allows you to control your server remotely. However, on Hetzner servers without KVM access, ISO installation is a slightly more complex process. This guide aims to provide a method that everyone can easily implement by explaining this process step by step.

1.1. Importance of Rescue Mode

Rescue Mode is vital for server administrators. Here are some important reasons:

• Data Recovery: Ideal for recovering data from a crashed operating system.
• System Repair: Used to fix a broken system or troubleshoot configuration issues.
• Operating System Installation: The only way to install a new operating system without KVM access.
• Security Scanning: Can be used to scan your server for malware.

1.2. Challenges of ISO Installation without KVM

Some challenges of performing ISO installation without KVM access include:

• Lack of Console Access: Without KVM, graphical interface or console access is not possible during installation.
• Network Configuration: Network configuration must be done manually during installation.
• Changing Boot Order: Since access to the BIOS is usually not possible, it is difficult to change the boot order.

2. Preparation Phase

Before starting the ISO installation, it is important to make the necessary preparations. This stage ensures that the installation is completed smoothly.

2.1. Required Tools and Software

• SSH Client: You will need an SSH client like PuTTY (Windows), Terminal (macOS/Linux) to connect to your server.
• ISO File: Download the ISO file of the operating system you want to install.
• Web Server: You will need a web server accessible over the internet to download the ISO file to your server (e.g., your own server or a file sharing service).
• Hetzner Customer Panel Access: You must have access to the Hetzner customer panel to put your server into Rescue Mode and manage it.

2.2. Preparing the ISO File

After downloading the ISO file, you need to upload it to a web server or make it accessible over the internet. This is usually done via an FTP client or the web server's control panel.

2.3. Gathering Network Information

You may need to assign a static IP address during installation. Therefore, it is important to collect your server's network information (IP address, network mask, gateway, DNS servers) in advance. You can obtain this information from the Hetzner customer panel or your server's current configuration.

3. Entering Rescue Mode

After the preparations are complete, you need to put your server into Rescue Mode.

3.1. Logging into the Hetzner Customer Panel

Log in to the Hetzner customer panel (Robot) and select your server.

3.2. Activating the Rescue System

On the server details page, find the "Rescue System" section and activate it. You will usually be asked for an SSH key or password. It is safer to use an SSH key. If you have not created an SSH key before, it is recommended that you create one. If you use the password option, make sure you choose a strong password.

3.3. Connecting to Rescue Mode via SSH

After Rescue Mode is activated, connect to your server via SSH with the IP address, username (usually "root") and password or SSH key provided to you.

ssh root@rescue_ip_address

4. ISO Installation Process

After connecting to Rescue Mode, you can start the ISO installation process.

4.1. Downloading the ISO File

In Rescue Mode, you need to download the ISO file to your server. You can download the ISO file using commands like `wget` or `curl`.

wget http://your_web_server.com/iso_file.iso

If the `wget` or `curl` commands are not available, you can update the package manager with the `apt-get update` command and then install the necessary packages.

apt-get update
apt-get install wget curl

4.2. Disk Partitioning

After downloading the ISO file, you need to partition your disk. This can be done with tools like `fdisk`, `parted`, or `gdisk`. Which tool you use depends on the operating system you want to install and your disk structure.

For example, a simple partitioning operation with `fdisk` can be done as follows:

fdisk /dev/sda

After running the `fdisk` command, follow these steps:

1. Press `g` to create a GPT partition table (if needed).
2. Press `n` to create a new partition.
3. Specify the partition number, first sector, and last sector.
4. Press `w` to save the changes.

Caution: Disk partitioning will erase your existing data. Therefore, be careful and make sure you have backups.

4.3. Creating the File System

After the disk partitioning process, you need to create a file system on the partition you created. This is done with the `mkfs` command. For example, to create an ext4 file system:

mkfs.ext4 /dev/sda1

4.4. Writing the ISO File to Disk

You can use the `dd` command to write the ISO file to disk. This command copies the contents of the ISO file directly to the disk.

dd if=iso_dosyasi.iso of=/dev/sda bs=4M status=progress

Caution: The `dd` command completely erases the contents of the disk and replaces it with the contents of the ISO file. Therefore, be careful and make sure you select the correct disk.

Alternatively, you can mount the ISO file using `loop mount` and copy the files to the disk partition. This method may be safer and more flexible in some cases.

4.5. Bootloader Installation

You need to install a bootloader for the operating system to start properly. GRUB (Grand Unified Bootloader) is one of the most commonly used bootloaders. To install GRUB, you must first mount the root directory:

mount /dev/sda1 /mnt

Then, you can install GRUB:

grub-install --target=i386-pc --root-directory=/mnt /dev/sda

This command installs GRUB to the `/dev/sda` disk and uses the `/mnt` directory as the root directory. To create the GRUB configuration file:

grub-mkconfig -o /mnt/boot/grub/grub.cfg

This command creates the GRUB configuration file in the `/mnt/boot/grub/grub.cfg` file.

4.6. Network Configuration

You may need to assign a static IP address during installation. Therefore, it is important to configure the network manually. Network configuration files are usually located in the `/etc/network/interfaces` or `/etc/netplan/` directory. Edit the correct file according to the operating system you are installing and enter your server's network information.

For example, to edit the `/etc/network/interfaces` file:

nano /etc/network/interfaces

Add a configuration like the following:

auto eth0
iface eth0 inet static
    address server_ip_address
    netmask network_mask
    gateway network_gateway
    dns-nameservers dns_server1 dns_server2

4.7. Reboot

After the installation is complete, you need to reboot your server. However, it is important to first unmount the root directory and exit Rescue Mode.

umount /mnt
exit

Remove your server from Rescue Mode in the Hetzner customer panel and reboot it. Your server should boot with the operating system you installed.

5. Post-Installation Checks

After your server has rebooted, it is important to check if the installation was successful.

5.1. SSH Connection

Try connecting to your server via SSH. If the connection is successful, the basic installation steps have been completed.

5.2. Checking Network Connection

Make sure the network connection is configured correctly. Try connecting to the internet with the `ping` command.

ping google.com

5.3. Checking Services

Make sure the necessary services (e.g., SSH, web server, database server) are running. You can check the services using your operating system's service management tools (e.g., `systemctl` or `service` commands).

6. Tips and Tricks

Here are some tips and tricks to make ISO installation easier and smoother:

• Verifying the ISO File: Verify the integrity of the ISO file you downloaded. A SHA256 or MD5 checksum is usually provided with the ISO file. You can use this value to check if the file was downloaded correctly.
• Using a Screen Recorder: Record the installation process with a screen recorder. This can help you diagnose problems more easily if you encounter them.
• Reviewing Log Files: Regularly review the log files generated during the installation. These files can help you identify and resolve errors.
• Getting Help from Forums and Communities: Don't hesitate to seek help from relevant forums or communities when you get stuck.

7. Real-Life Examples and Case Studies

Example 1: An e-commerce site owner wanted to install a new operating system on their server. However, since they did not have KVM access, they performed the ISO installation via Rescue Mode. By following the step-by-step instructions, they successfully installed the operating system and got the e-commerce site up and running again.

Example 2: A system administrator used Rescue Mode to recover data from a crashed server. By putting the server into Rescue Mode, they accessed the disk partition and copied important data to another server. This prevented data loss.

8. Visual Explanations

Schema:

Rescue Mode -> Downloading ISO File -> Disk Partitioning -> Creating File System -> Writing ISO File to Disk -> Bootloader Installation -> Network Configuration -> Reboot

Graphic (Textual Description):

Installation Process Completion Rate:

Preparation (10%) -> Rescue Mode (10%) -> ISO Download (15%) -> Disk Partitioning (15%) -> File System (10%) -> ISO Writing (20%) -> Bootloader (10%) -> Network Configuration (10%)

9. Frequently Asked Questions

• Question 1: How can I access Rescue Mode?
• Answer: You can activate Rescue Mode by selecting your server from the Hetzner customer panel (Robot).
• Question 2: How can I download the ISO file?
• Answer: You can download the ISO file using commands like `wget` or `curl`.
• Question 3: Is the disk partitioning process safe?
• Answer: The disk partitioning process will erase your existing data. Therefore, be careful and make sure you have backups.
• Question 4: Why is bootloader installation important?
• Answer: The bootloader ensures that the operating system starts properly. Without a bootloader, your server will not boot.
• Question 5: How can I configure the network?
• Answer: Network configuration files are usually located in the `/etc/network/interfaces` or `/etc/netplan/` directory. Edit the correct file according to the operating system you are installing and enter your server's network information.
• Question 6: Can this method be applied on Hetzner Cloud Germany Location Servers?
• Answer: This method is generally valid for dedicated servers. KVM access is usually available for Hetzner Cloud servers, and ISO installation can be done more easily.

10. Conclusion and Summary

Hetzner Rescue Mode is an effective way to install ISO on servers without KVM access. In this guide, all steps such as entering Rescue Mode, downloading the ISO file, disk partitioning, creating a file system, writing the ISO file to disk, bootloader installation, network configuration, and post-installation checks are explained in detail. In addition, with tips, tricks, real-life examples, and frequently asked questions, it is aimed that the reader fully understands the subject and makes a successful installation. By following this guide, you can easily install ISO on your Hetzner server.

Important points:

• Backup: Remember to back up your data before installation.
• Caution: Be careful during disk partitioning and ISO writing. Incorrect disk selection may cause data loss.
• Patience: The installation process may take time. Be patient and follow the steps carefully.