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Using the Rescue CD diagnostics and recovery tools

Written by
Updated at December 1, 2025

If you cannot boot the main server OS, you can start the server using the SystemRescue CD that includes essential utilities and is accessible via the KVM console.

Boot the server from a Rescue CD

  1. In the management console, select the folder containing your server.

  2. Go to BareMetal.

  3. Find the server you need in the list, click in its row, and select KVM console.

  4. Click the CD icon or select Media → Virtual Media Wizard... in the top menu of the KVM console window. In the window that opens:

    1. In the CD/DVD Media1 section, click Browse and select the systemrescue<...>.iso image in the common-iso directory.
    2. Click Connect CD/DVD.
    3. Check the Virtual CD 1 device Status section to make sure the Connected To field now shows your selected CD image path, then click Close.

  5. To boot the server from the selected Rescue CD image, click Reboot to CD-ROM in the top-right corner of the KVM console.

  6. Wait for the server to restart and for the main SystemRescue menu to load. Select the required menu item using the up and down arrow keys, then press Enter.

    SystemRescue main menu elements

    • Boot SystemRescue using default options

      Launches the SystemRescue recovery interface with default settings.

    • Boot SystemRescue and copy system to RAM (copyram)

      Launches the SystemRescue recovery interface, copying the essential utilities and OS system files to RAM for operation.

    • Boot SystemRescue and verify integrity of the medium (checksum)

      Launches the SystemRescue recovery interface with Rescue CD media integrity verification.

    • Boot SystemRescue using basic display drivers (nomodeset)

      Launches the SystemRescue recovery interface with basic video drivers for GUI mode.

    • Boot SystemRescue with serial console (ttyS0,115200n8)

      Launches the SystemRescue recovery interface in text mode via serial console.

    • Boot SystemRescue, do not activate md raid or lvm (nomdlvm)

      Launches the SystemRescue recovery interface with RAID support disabled.

    • Boot a Linux operating system installed on the disk (findroot)

      Boots the Linux installation from the server’s primary boot disk.

    • Stop during the boot process before mounting the root filesystem

      Boots the OS installed on the server's primary boot disk, stopping the boot process before root filesystem mount.

    • Boot existing OS

      Boots the OS installed on the server. Use the Tab key to pre-select the disk and partition number containing the OS installation.

    • Run Memtest86+ (RAM test)

      Runs the Memtest86+ RAM testing utility.

    • Reboot

      Reboots the server.

    • Power Off

      Powers off the server.

Using SystemRescue toolkit

Use SystemRescue tools to restore or configure your server:

  1. Boot the server using the Rescue CD.

  2. In the main SystemRescue menu, select Boot SystemRescue using default options.

  3. Once you launch SystemRescue, a terminal session will open in the KVM console. In the terminal, enter Manual.

    You will access the ELinks browser allowing you to browse SystemRescue documentation and explore its features.

    To exit ELinks, press Esc, use the up and down arrow keys to select Exit in the menu, then press Enter. Confirm the exit.

You can also access SystemRescue documentation using graphical user interface.

  1. Boot the server using the Rescue CD.

  2. In the main SystemRescue menu, select Boot SystemRescue using default options.

    Running SystemRescue will launch the SystemRescue terminal in the KVM console. Run the following commands in the terminal.

  3. Identify the label of the server partition you need to mount:

    blkid

    Result:

    /dev/md127: LABEL="/" UUID="97e4ad6e-edd9-4574-b4b3-23a86f2a701e" BLOCK_SIZE="4096" TYPE="ext4"
/dev/sdb4: UUID="29395ea9-a41c-c71c-2807-2f5889e52967" UUID_SUB="287cdff0-ba68-6981-f46e-e52e0bf2d799" LABEL="3" TYPE="linux_raid_member" PARTLABEL="primary" PARTUUID="d6ad0b56-8291-4e0b-ad93-85d98e078ecf"
/dev/sdb2: UUID="557a2516-47d1-a676-2cad-fa629a418c1f" UUID_SUB="27dfdf6c-c521-c0f3-e52c-46e2b728c0c1" LABEL="1" TYPE="linux_raid_member" PARTLABEL="primary" PARTUUID="b4483bff-0bb2-4077-a530-b64daa4b6fff"
/dev/sdb3: UUID="20426859-f357-0447-6123-af035e85ca01" UUID_SUB="4dd828b0-4b6d-ea13-a9b9-cbeb5aaa0917" LABEL="2" TYPE="linux_raid_member" PARTLABEL="primary" PARTUUID="8e624512-5665-4c11-aa0b-ecbcdb7b1d7a"
/dev/sdb1: PARTLABEL="primary" PARTUUID="b152360c-3157-482e-9804-36620f654ec1"
/dev/md125: LABEL="/boot" UUID="58a6d4a4-d20a-4125-b52c-f76529a398f4" BLOCK_SIZE="4096" TYPE="ext3"
...
/dev/sda1: PARTLABEL="primary" PARTUUID="1a1c7c88-4cce-429f-984f-1626587626c3"

    For example, the server OS partition has the md127 label. Save this value as it will be required for mounting the disk later.

  4. Create a local directory to serve as the mount point for the partition:

    mkdir /mnt/serverdisk

  5. Mount the selected partition using the label you saved earlier:

    mount /dev/<partition_label> /mnt/serverdisk

  6. Navigate to the mounted disk:

    cd /mnt/serverdisk

    Here you can access the operating system directory tree:

    ls -l

    Result:

    total 64
lrwxrwxrwx   1 root root     7 Jul  8 10:47 bin -> usr/bin
drwxr-xr-x   4 root root  4096 Oct 23 12:09 boot
drwxr-xr-x  21 root root  4360 Oct 24 05:43 dev
drwxr-xr-x  91 root root  4096 Oct 23 12:09 etc
drwxr-xr-x   2 root root  4096 Apr 18  2022 home
lrwxrwxrwx   1 root root     7 Jul  8 10:47 lib -> usr/lib
lrwxrwxrwx   1 root root     9 Jul  8 10:47 lib32 -> usr/lib32
lrwxrwxrwx   1 root root     9 Jul  8 10:47 lib64 -> usr/lib64
lrwxrwxrwx   1 root root    10 Jul  8 10:47 libx32 -> usr/libx32
drwx------   2 root root 16384 Oct 18 14:33 lost+found
drwxr-xr-x   2 root root  4096 Jul  8 10:47 media
drwxr-xr-x   2 root root  4096 Oct 23 20:08 mnt
drwxr-xr-x   2 root root  4096 Jul  8 10:47 opt
dr-xr-xr-x 482 root root     0 Oct 24 05:43 proc
drwx------   5 root root  4096 Oct 23 12:05 root
drwxr-xr-x  25 root root   800 Oct 24 05:43 run
lrwxrwxrwx   1 root root     8 Jul  8 10:47 sbin -> usr/sbin
drwxr-xr-x   2 root root  4096 Oct 18 14:43 snap
drwxr-xr-x   2 root root  4096 Jul  8 10:47 srv
dr-xr-xr-x  13 root root     0 Oct 24 05:43 sys
drwxrwxrwt  12 root root  4096 Oct 24 05:43 tmp
drwxr-xr-x  14 root root  4096 Jul  8 10:47 usr
drwxr-xr-x  14 root root  4096 Oct 18 14:38 var

  1. Boot the server using the Rescue CD.

  2. In the main SystemRescue menu, select Boot SystemRescue using default options.

    Once you launch SystemRescue, a terminal session will open in the KVM console.

  3. To launch the SystemRescue GUI, run the startx command in the terminal.

    This command starts the SystemRescue graphical user interface, which includes a web browser with internet access, along with diagnostics and computer management tools.

  1. Boot the server using the Rescue CD.

  2. In the main SystemRescue menu, select Run Memtest86+ (RAM test).

  3. Once the Memtest86+ window opens, wait for the RAM test to complete.

    To cancel the test and reboot the server, press Esc.

See also

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