Prepare an Ubuntu virtual machine for Azure
Applies to: ✔️ Linux VMs ✔️ Flexible scale sets
Ubuntu now publishes official Azure VHDs for download at https://cloud-images.ubuntu.com/. If you need to build your own specialized Ubuntu image for Azure, rather than use the manual procedure below it's recommended to start with these known working VHDs and customize as needed. The latest image releases can always be found at the following locations:
- Ubuntu 18.04/Bionic: bionic-server-cloudimg-amd64-azure.vhd.zip
- Ubuntu 20.04/Focal: focal-server-cloudimg-amd64-azure.vhd.zip
This article assumes that you've already installed an Ubuntu Linux operating system to a virtual hard disk. Multiple tools exist to create .vhd files, for example a virtualization solution such as Hyper-V. For instructions, see Install the Hyper-V Role and Configure a Virtual Machine.
Ubuntu installation notes
- Please see also General Linux Installation Notes for more tips on preparing Linux for Azure.
- The VHDX format isn't supported in Azure, only fixed VHD. You can convert the disk to VHD format using Hyper-V Manager or the
- When installing the Linux system it's recommended that you use standard partitions rather than LVM (often the default for many installations). This will avoid LVM name conflicts with cloned VMs, particularly if an OS disk ever needs to be attached to another VM for troubleshooting. LVM or RAID may be used on data disks if preferred.
- Don't configure a swap partition or swapfile on the OS disk. The cloud-init provisioning agent can be configured to create a swap file or a swap partition on the temporary resource disk. More information about this can be found in the steps below.
- All VHDs on Azure must have a virtual size aligned to 1MB. When converting from a raw disk to VHD you must ensure that the raw disk size is a multiple of 1MB before conversion. See Linux Installation Notes for more information.
Before attempting to create your own custom Ubuntu image for Azure, please consider using the pre-built and tested images from https://cloud-images.ubuntu.com/ instead.
In the center pane of Hyper-V Manager, select the virtual machine.
Click Connect to open the window for the virtual machine.
Replace the current repositories in the image to use Ubuntu's Azure repository.
/etc/apt/sources.list, it's recommended to make a backup:
# sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak
Ubuntu 18.04 and Ubuntu 20.04:
# sudo sed -i 's/http:\/\/archive\.ubuntu\.com\/ubuntu\//http:\/\/azure\.archive\.ubuntu\.com\/ubuntu\//g' /etc/apt/sources.list # sudo sed -i 's/http:\/\/[a-z][a-z]\.archive\.ubuntu\.com\/ubuntu\//http:\/\/azure\.archive\.ubuntu\.com\/ubuntu\//g' /etc/apt/sources.list # sudo apt-get update
The Ubuntu Azure images are now using the Azure-tailored kernel. Update the operating system to the latest Azure-tailored kernel and install Azure Linux tools (including Hyper-V dependencies) by running the following commands:
Ubuntu 18.04 and Ubuntu 20.04:
# sudo apt update # sudo apt install linux-azure linux-image-azure linux-headers-azure linux-tools-common linux-cloud-tools-common linux-tools-azure linux-cloud-tools-azure (recommended) # sudo apt full-upgrade # sudo reboot
Modify the kernel boot line for Grub to include additional kernel parameters for Azure. To do this open
/etc/default/grubin a text editor, find the variable called
GRUB_CMDLINE_LINUX_DEFAULT(or add it if needed) and edit it to include the following parameters:
GRUB_CMDLINE_LINUX_DEFAULT="console=tty1 console=ttyS0,115200n8 earlyprintk=ttyS0,115200 rootdelay=300 quiet splash"
Save and close this file, and then run
sudo update-grub. This will ensure all console messages are sent to the first serial port, which can assist Azure technical support with debugging issues.
Ensure that the SSH server is installed and configured to start at boot time. This is usually the default.
Install cloud-init (the provisioning agent) and the Azure Linux Agent (the guest extensions handler). Cloud-init uses
netplanto configure the system network configuration (during provisioning and each subsequent boot) and
gdiskto partition resource disks.
# sudo apt update # sudo apt install cloud-init gdisk netplan.io walinuxagent && systemctl stop walinuxagent
walinuxagentpackage may remove the
NetworkManager-gnomepackages, if they are installed.
Remove cloud-init default configs and leftover
netplanartifacts that may conflict with cloud-init provisioning on Azure:
# rm -f /etc/cloud/cloud.cfg.d/50-curtin-networking.cfg /etc/cloud/cloud.cfg.d/curtin-preserve-sources.cfg /etc/cloud/cloud.cfg.d/99-installer.cfg /etc/cloud/cloud.cfg.d/subiquity-disable-cloudinit-networking.cfg # rm -f /etc/cloud/ds-identify.cfg # rm -f /etc/netplan/*.yaml
Configure cloud-init to provision the system using the Azure datasource:
# cat > /etc/cloud/cloud.cfg.d/90_dpkg.cfg << EOF datasource_list: [ Azure ] EOF # cat > /etc/cloud/cloud.cfg.d/90-azure.cfg << EOF system_info: package_mirrors: - arches: [i386, amd64] failsafe: primary: http://archive.ubuntu.com/ubuntu security: http://security.ubuntu.com/ubuntu search: primary: - http://azure.archive.ubuntu.com/ubuntu/ security:  - arches: [armhf, armel, default] failsafe: primary: http://ports.ubuntu.com/ubuntu-ports security: http://ports.ubuntu.com/ubuntu-ports EOF # cat > /etc/cloud/cloud.cfg.d/10-azure-kvp.cfg << EOF reporting: logging: type: log telemetry: type: hyperv EOF
Configure the Azure Linux agent to rely on cloud-init to perform provisioning. Have a look at the WALinuxAgent project for more information on these options.
sed -i 's/Provisioning.Enabled=y/Provisioning.Enabled=n/g' /etc/waagent.conf sed -i 's/Provisioning.UseCloudInit=n/Provisioning.UseCloudInit=y/g' /etc/waagent.conf sed -i 's/ResourceDisk.Format=y/ResourceDisk.Format=n/g' /etc/waagent.conf sed -i 's/ResourceDisk.EnableSwap=y/ResourceDisk.EnableSwap=n/g' /etc/waagent.conf cat >> /etc/waagent.conf << EOF # For Azure Linux agent version >= 2.2.45, this is the option to configure, # enable, or disable the provisioning behavior of the Linux agent. # Accepted values are auto (default), waagent, cloud-init, or disabled. # A value of auto means that the agent will rely on cloud-init to handle # provisioning if it is installed and enabled, which in this case it will. Provisioning.Agent=auto EOF
Clean cloud-init and Azure Linux agent runtime artifacts and logs:
# sudo cloud-init clean --logs --seed # sudo rm -rf /var/lib/cloud/ # sudo systemctl stop walinuxagent.service # sudo rm -rf /var/lib/waagent/ # sudo rm -f /var/log/waagent.log
Run the following commands to deprovision the virtual machine and prepare it for provisioning on Azure:
sudo waagent -force -deprovision+usercommand generalizes the image by attempting to clean the system and make it suitable for re-provisioning. The
+useroption deletes the last provisioned user account and associated data.
Deprovisioning using the command above does not guarantee that the image is cleared of all sensitive information and is suitable for redistribution.
# sudo waagent -force -deprovision+user # rm -f ~/.bash_history # export HISTSIZE=0 # logout
Click Action -> Shut Down in Hyper-V Manager.
Azure only accepts fixed-size VHDs. If the VM's OS disk isn't a fixed-size VHD, use the
Convert-VHDPowerShell cmdlet and specify the
-VHDType Fixedoption. Please have a look at the docs for
To bring a Generation 2 VM on Azure, follow these steps:
Change directory to the boot EFI directory:
# cd /boot/efi/EFI
Copy the ubuntu directory to a new directory named boot:
# sudo cp -r ubuntu/ boot
Change directory to the newly created boot directory:
# cd boot
Rename the shimx64.efi file:
# sudo mv shimx64.efi bootx64.efi
Rename the grub.cfg file to bootx64.cfg:
# sudo mv grub.cfg bootx64.cfg
You're now ready to use your Ubuntu Linux virtual hard disk to create new virtual machines in Azure. If this is the first time that you're uploading the .vhd file to Azure, see Create a Linux VM from a custom disk.
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