Determining the Bootloader and Kernel/Ramdisk Loading in a KVM VM
==================================================================

We are trying to determine which bootloader is in use by the VM and confirm from where the kernel (``vmlinuz``) and initial RAM disk (``initrd``) are being loaded. Since the VM is running on **KVM (Kernel-based Virtual Machine)**, let’s explore the possible bootloaders and how they load the kernel and initramfs.

Step 1: Verify the Bootloader in Use
--------------------------------------------------

To determine the bootloader in use, we can check the following:

1. **Check for GRUB**:

   - GRUB is the most common bootloader for Linux systems. Check if GRUB is installed and configured:
     - Look for the GRUB configuration file:
     
       .. code-block:: bash
          ls /boot/grub2/grub.cfg
          
     - Check if GRUB is installed:
     
       .. code-block:: bash
          grub2-install --version

2. **Check for systemd-boot**:

   - Although ``bootctl status`` confirmed the system is not booted with EFI, it’s worth checking for systemd-boot configuration files:
     - Look for the systemd-boot configuration directory:
     
       .. code-block:: bash
          ls /boot/loader/entries/

3. **Check for Other Bootloaders**:

   - If neither GRUB nor systemd-boot is in use, the system might be using a different bootloader (e.g., Syslinux, LILO, or a custom bootloader).
     - Look for configuration files in ``/boot/``:
     
       .. code-block:: bash
          ls /boot/

Step 2: Confirm Kernel and Initramfs Loading
--------------------------------------------------

Once the bootloader is identified, we need to confirm how the kernel and initramfs are being loaded.

1. **If GRUB is in Use**:

   - The GRUB configuration file (``/boot/grub2/grub.cfg``) should contain entries like:
   
     .. code-block:: bash
        menuentry 'Linux Distribution' {
            set root='hd0,msdos1'
            linux /boot/vmlinuz-<version> root=/dev/sda1
            initrd /boot/initrd.img-<version>
        }
        
   - If these entries are missing, GRUB might be using a custom configuration or chainloading another bootloader.

2. **If systemd-boot is in Use**:

   - The systemd-boot configuration files in ``/boot/loader/entries/`` should contain entries like:
   
     .. code-block:: ini
        title Linux Distribution
        version 5.15.0-83-generic
        linux /boot/vmlinuz-5.15.0-83-generic
        initrd /boot/initrd.img-5.15.0-83-generic
        options root=/dev/sda1

3. **If Another Bootloader is in Use**:

   - Check the bootloader’s configuration files (e.g., ``syslinux.cfg`` for Syslinux or ``lilo.conf`` for LILO) for references to the kernel and initramfs.

Step 3: Analyze the Boot Process
--------------------------------------------------

To further understand how the kernel and initramfs are being loaded, we can analyze the boot process:

1. **Check the Kernel Command Line**:

   - Run the following command to inspect the kernel command line:
   
     .. code-block:: bash
        cat /proc/cmdline
        
   - Look for parameters like ``initrd=`` or ``root=`` that indicate how the kernel and initramfs are loaded.

2. **Inspect the** ``dmesg`` **Output**:

   - The ``dmesg`` output provides detailed logs of the boot process. Look for messages related to the kernel and initramfs loading:
   
     .. code-block:: bash
        dmesg | grep -iE 'linux|initrd|smpboot'

3. **Check for Paravirtualized Drivers**:

   - Since the VM is running on KVM, look for messages related to paravirtualized drivers (e.g., ``virtio``):
   
     .. code-block:: bash
        dmesg | grep -i virtio

Step 4: Verify Hypervisor Configuration
--------------------------------------------------

Since the VM is running on KVM, the hypervisor configuration might influence how the kernel and initramfs are loaded:

1. **Check the VM Configuration**:

   - Verify the VM’s configuration file (e.g., ``/etc/libvirt/qemu/<vm-name>.xml`` for libvirt) to ensure the correct bootloader and kernel are specified.

2. **Check for Direct Kernel Boot**:

   - Some hypervisors allow direct kernel boot, bypassing the bootloader. Check if the VM is configured to boot the kernel directly:
   
     .. code-block:: bash
        grep -i kernel /etc/libvirt/qemu/<vm-name>.xml

Summary
--------------------------------------------------

1. Verify the bootloader in use (GRUB, systemd-boot, or another bootloader).
2. Confirm how the kernel and initramfs are being loaded by inspecting the bootloader configuration files.
3. Analyze the boot process using ``dmesg`` and the kernel command line.
4. Verify the hypervisor configuration to ensure the correct bootloader and kernel are being used.

Let me know if you need further clarification or assistance!