Bare Metal Recovery Instructions for Azure

Azure virtual machines cannot boot from ISO images. To enable Bare Metal Recovery (BMR) in Azure, use Linux Rescue Media in VHD format.

This VHD image is designed specifically for Azure and includes:

cloud-init for automated configuration
Azure Linux VM Agent for integration with Azure services
Compatibility with the Azure Serial Console, which you can use to perform BMR through the Azure portal

Using this VHD ensures a seamless recovery experience in Azure environments.

BMR on Azure involves the following:

Download the rescue VHD file
Upload the rescue VHD file to Azure Blob Storage
Create a Managed disk from the rescue VHD file
Attach the Managed disk to the target machine
Boot the target machine
Perform recovery
Boot the target machine from recovered OS disk

Requirements

Before beginning, ensure you have:

An Azure Storage account
To create an Azure storage account, go to Create an Azure storage account
A container in Azure Blob Storage
To create a container and upload files to Azure Blob Storage, go to Quickstart: Upload files to Azure Blob Storage

Instructions

Download the Linux Rescue Media in VHD format from:

Session-specific rescue VHD files are not supported. It is not possible restore VHD files from the Backup Manager Restore tab.

Upload the rescue VHD file to Azure Blob Storage either via the Azure portal or by using the following Azure CLI command:
```
az storage blob upload \
    --account-name <storage-account> \
    --container-name <container> \
    --file <path-to-vhd-file> \
    --name <vhd-file-name> \
    --auth-mode login
```
Ensure you replace the placeholder values in angle brackets (< >) with the relevant information

For example:

az storage blob upload \
    --account-name coverescuestorageaccount \
    --container-name cove-rescue-media-container \
    --name cove-rescue-media-linux.vhd \
    --file ~/Downloads/cove-rescue-media-linux.vhd \
    --auth-mode login

Use the az disk create command to create a managed disk in Azure from the VHD file uploaded to Azure Blob Storage.

az disk create \
    --resource-group <resource-group> \
    --name <managed-disk-name> \
    --source https://<storage-account>.blob.core.windows.net/<container>/<vhd-file-name> \
    --location <location> \
    --zone <zone> \
    --os-type Linux \
    --security-type <security-type> \
    --architecture x64 \
    --sku <sku> \
    --hyper-v-generation <hyper-v-generation>

Ensure you replace the placeholder values in angle brackets (< >) with the relevant information

For example:

az disk create \
    --resource-group DefaultResourceGroup \
    --name cove-rescue-media-linux \
    --source https://coverescuestorageaccount.blob.core.windows.net/cove-rescue-media-container/cove-rescue-media-linux.vhd \
    --location eastus \
    --zone 1 \
    --os-type Linux \
    --security-type TrustedLaunch \
    --architecture x64 \
    --sku Premium_LRS \
    --hyper-v-generation V2

The values for parameters such as resource group, zone, security type, and Hyper-V generation must match the target virtual machine. If they do not match, the managed disk cannot be attached as the OS disk to the virtual machine.

Attach the managed disk with the rescue system to the target virtual machine.
1. If the target and source machines are the same:
  1. Login to the Azure portal
  2. Navigate to the Disks page for the target VM.
  3. Swap the OS disk so that the managed disk containing the rescue system becomes the OS disk.
  4. Attach the original OS disk as a data disk.
    This step is required because the original OS disk will be recovered; it will be repartitioned, and files and folders will be restored on it. For more information, see Swap the OS disk.
2. If the target machine is a new blank VM, you must migrate the source system to a new VM. To do so:
  1. Create blank managed disks that match the size and number of disks on the source machine.
    The disk that will become the OS disk after recovery must have the same OS type, Hyper-V generation, and security type as the target VM. This disk cannot be created in the Azure portal. Use the Azure CLI instead.
  2. Use the az disk create command to create the OS disk.
```
az disk create \
    --resource-group <resource group> \
    --name <disk name> \
    --size-gb <disk size> \
    --os-type Linux \
    --hyper-v-generation <hyper-v-generation> \
    --sku <sku> \
    --security-type <security-type> \
    --zone <zone>
```
    Ensure you replace the placeholder values in angle brackets (< >) with the relevant information
  3. Go to the managed disk that contains the rescue system and select Create VM to create the target virtual machine from this disk.
  4. During target VM creation, attach the blank disks as data disks.
    During recovery, the attached data disks will be repartitioned, and files and folders will be restored on them.
Boot the target VM:
1. Go to the target VM’s Overview page
2. Verify that the managed disk containing the rescue system is attached as the OS disk
3. Select Start.
Perform recovery via SSH or Azure Serial Console. You can recover the system by either:
- Setting up an SSH connection to the target VM
- Using the Azure Serial Console

For details on connecting to a VM, see Connect to the VM in the official Microsoft Azure documentation.

Run the cove recover command to start the recovery process:
cove recover
If you connect to the VM over SSH using a non-root account, run sudo cove recover. The recovery script requires root privileges.

For more information about the recovery process, see the Bare Metal Recovery for Linux instructions. The process is the same as performing recovery with the Cove Rescue ISO image in hypervisor environments.

Boot the target machine from the recovered OS disk after recovery completes:
1. Detach the Cove Rescue managed disk from the target VM.
2. Swap the original OS disk back so the VM boots from the recovered OS disk.
3. Start the VM and verify that the system has been successfully recovered.