Boot the server in recovery and diagnostic mode

Last update: October 05 2026Open in Markdown

If the server does not boot or is unreachable over the network, boot it in one of the recovery and diagnostic modes. Once booted, you can diagnose the server and fix OS configuration errors.

If the server becomes unreachable some time after a reboot, check if sleep mode is enabled in the OS. Sleep mode can be enabled automatically when installing certain analytics packages (anaconda, cudatoolkit, nvidiautils, etc.). For an example of diagnosing and disabling sleep mode, see the Selectel blog post How to disable sleep mode in Ubuntu.

If you experience issues with Mac Mini M1 and Raspberry Pi servers, submit a ticket.

1. Select the recovery and diagnostic mode.
2. Change the server boot template.
3. Connect to the server.
4. Restore the previous server boot template.

1. Select a recovery and diagnostic mode

Recovery and diagnostic modes provide full access to the server file system.

We recommend using a recovery and diagnostic mode based on your tasks and server OS:

• Rescue — for Linux servers;
• WinPE — for Windows servers;
• Boot menu — for any server OS;
• Veeam Recovery Media 13 for Windows — for restoring a server from a backup;
• Talos — for working with Kubernetes.

Rescue

Rescue is a recovery mode that loads the operating system into RAM without using the server's local drives. It contains pre-installed tools for system diagnostics and recovery . You can install additional tools yourself using the package manager pacman.

You can connect to the server in Rescue via SSH or via the KVM console.

During the first authorization on the server, the SSH key is saved to the ~/.ssh/known_hosts file. If the server was rebooted, the REMOTE HOST IDENTIFICATION HAS CHANGED error may appear during subsequent authorization. To fix it, delete the host information by IP address:

ssh-keygen -f "/home/<username>/.ssh/known_hosts" -R "<ip_address>"

Specify:

• <username> — username (login). You can view it in the Control panel: in the top menu, click Products → Dedicated Servers → Servers → server page → Operating System tab → Login field;
• <ip_address> — public IP address of the server. You can view it in the Control panel: in the top menu, click Products → Dedicated Servers → Servers → server page → Operating System tab → IP field.

WinPE

WinPE is a minimal version of Windows OS with limited services. It runs in the server's RAM. It is used for diagnosing, recovering, and installing Windows OS. For details, see the Windows PE guide in Microsoft documentation.

You can connect to the server in WinPE via VNC or via the KVM console.

Boot menu

Boot menu is a menu for diagnosing and recovering the system, and booting the most common server operating systems. The Tools and Utilities section provides tools for diagnostics and recovery:

• GParted — creating and partitioning disks;
• Clonezilla — creating backups. For servers in UEFI, use an image mounted via the KVM console;
• Memtest86 — testing RAM.

You can connect to the server in Boot menu via the KVM console.

Veeam Recovery Media 13 for Windows

Veeam Recovery Media 13 for Windows is a WinPE-based boot environment designed for restoring servers and workstations from backups.

Runs in the server's RAM. It is used for full system recovery, as well as for recovering individual drives, partitions, and files with connection to remote backup storage.

You can connect to the server in Veeam Recovery Media 13 for Windows via VNC or via the KVM console.

Talos

Talos Linux is a specialized operating system for running Kubernetes, developed by Sidero Labs.

It runs in the server's RAM and uses the latest Talos version from official releases — for details, see the Releases page in the Sidero Labs GitHub repository.

You can connect to the server in Talos via VNC or via the KVM console.

For more information on how to install Talos Linux on a dedicated server for working with Kubernetes, see the Install Talos Linux for Kubernetes instructions.

2. Change the server boot template

1. In the Control panel, in the top menu, click Products and select Dedicated Servers.

2. In the Servers section, open the server page → tab Operating System.

3. Click Change boot template.

4. Select a boot template:

   • Boot to Rescue;
   • Boot to WinPE;
   • Boot to Boot menu;
   • Boot to Veeam Recovery Media 13 for Windows;
   • Boot to Talos.

5. In the New password field, click . A new password will be generated — it is used only to connect to the server in recovery and diagnostic mode.

6. Click Save and reboot. The server will be rebooted, and all data on it will be preserved.

3. Connect to the server

The password for connecting to the server in recovery and diagnostic mode can be viewed in the Control panel in the menu Products → Dedicated Servers → Servers → server page → Operating System tab. You generated the password when changing the server boot template in step 5.

The connection process depends on the selected recovery and diagnostics mode:

• in all modes — via the KVM console. For Chipcore Line servers, you can order the additional service Connect IP-KVM for 3 hours;
• in Rescue — via SSH — to protect servers from attacks, when connecting to a server in Rescue, the number of authorization attempts is limited. If there are 10 unsuccessful connection attempts from a single IP address within an hour, this IP address will be blocked for 24 hours. To unblock the IP address earlier, reboot the server;
• in WinPE — via VNC;
• in Veeam Recovery Media 13 for Windows — via VNC;
• in Talos — via VNC.

4. Return to the previous server boot template

When rebooting the server from the OS, the boot template will automatically change back to the one that was set before changing the server boot template.

1. In the Control panel, in the top menu, click Products and select Dedicated Servers.
2. In the Servers section, open the server page → tab Operating System.
3. Click Change boot template.
4. In the Boot template field, select the previous boot template.
5. Click Save and reboot.