Prepare a Red Hat-based virtual machine for Azure
Applies to: ✔️ Linux VMs ✔️ Flexible scale sets ✔️ Uniform scale sets
In this article, you learn how to prepare a Red Hat Enterprise Linux (RHEL) virtual machine (VM) for use in Azure. The versions of RHEL that are covered in this article are 6.X, 7.X, and 8.X. The hypervisors for preparation that are covered in this article are Hyper-V, kernel-based VM (KVM), and VMware.
For more information about eligibility requirements for participating in Red Hat's Cloud Access program, see the Red Hat Cloud Access website and Running RHEL on Azure. For ways to automate building RHEL images, see Azure Image Builder.
Note
Be aware of versions that are at their end of life (EOL) and are no longer supported by Red Hat. Uploaded images that are at or beyond EOL are supported on a reasonable business-effort basis. For more information, see the Red Hat Product Life Cycles.
Hyper-V Manager
This section shows you how to prepare a RHEL 6, RHEL 7, or RHEL 8 VM by using Hyper-V Manager.
Prerequisites
This section assumes that you've already obtained an ISO file from the Red Hat website and installed the RHEL image to a virtual hard disk (VHD). For more information about how to use Hyper-V Manager to install an operating system image, see Install the Hyper-V role and configure a virtual machine.
RHEL installation notes
- Azure doesn't support the VHDX format. Azure supports only fixed VHD. You can use Hyper-V Manager to convert the disk to VHD format, or you can use the
convert-vhd
cmdlet. If you use VirtualBox, select Fixed size as opposed to the default dynamically allocated option when you create the disk. - Azure supports Gen1 (BIOS boot) and Gen2 (UEFI boot) VMs.
- The maximum size that's allowed for the VHD is 1,023 GB.
- The vfat kernel module must be enabled in the kernel.
- Logical Volume Manager (LVM) is supported and can be used on the OS disk or data disks in Azure VMs. In general, we recommend that you use standard partitions on the OS disk rather than LVM. This practice avoids LVM name conflicts with cloned VMs, particularly if you ever need to attach an operating system disk to another identical VM for troubleshooting. For more information, see the LVM and RAID documentation.
- Kernel support for mounting Universal Disk Format (UDF) file systems is required. At first boot on Azure, the UDF-formatted media that's attached to the guest passes the provisioning configuration to the Linux VM. The Azure Linux agent must be able to mount the UDF file system to read its configuration and provision the VM. Without this step, provisioning fails.
- Don't configure a swap partition on the operating system disk. For more information, read the following steps.
- All VHDs on Azure must have a virtual size aligned to 1 MB. When you convert from a raw disk to VHD, you must ensure that the raw disk size is a multiple of 1 MB before conversion. For more information, read the following steps. See also Linux installation notes.
Note
Cloud-init >= 21.2 removes the UDF requirement. However, without the UDF module enabled, the CD-ROM won't mount during provisioning, which prevents custom data from being applied. A workaround is to apply custom data by using user data. Unlike custom data, user data isn't encrypted. For more information, see User data formats.
RHEL 6 using Hyper-V Manager
Important
On November 30, 2020, RHEL 6 reached the end of the Maintenance phase. The Maintenance phase is followed by the Extended Life phase. As RHEL 6 transitions out of the Full/Maintenance phases, we strongly recommend that you upgrade to RHEL 7, 8, or 9. If you must stay on RHEL 6, we recommend that you add the RHEL Extended Life Cycle Support Add-on.
In Hyper-V Manager, select the VM.
Select Connect to open a console window for the VM.
In RHEL 6,
NetworkManager
can interfere with the Azure Linux agent. Uninstall this package:sudo rpm -e --nodeps NetworkManager
Create or edit the
/etc/sysconfig/network
file, and add the following text:NETWORKING=yes HOSTNAME=localhost.localdomain
Create or edit the
/etc/sysconfig/network-scripts/ifcfg-eth0
file, and add the following text:DEVICE=eth0 ONBOOT=yes BOOTPROTO=dhcp TYPE=Ethernet USERCTL=no PEERDNS=yes IPV6INIT=no
Move (or remove) the udev rules to avoid generating static rules for the Ethernet interface. These rules cause problems when you clone a VM in Azure or Hyper-V:
Warning
Many 'v5' and newer VM sizes require Accelerated Networking. If it isn't enabled, NetworkManager will assign the same IP address to all virtual function interfaces. To prevent duplicate IP addresses, make sure to include this udev rule when migrating to a newer size.
sudo ln -s /dev/null /etc/udev/rules.d/75-persistent-net-generator.rules sudo rm -f /etc/udev/rules.d/70-persistent-net.rules
Note
When you use Accelerated Networking, the synthetic interface that's created must be configured to be unmanaged by using a udev rule. This action prevents
NetworkManager
from assigning the same IP to it as the primary interface.To apply it:
sudo cat <<EOF>> /etc/udev/rules.d/68-azure-sriov-nm-unmanaged.rules # Accelerated Networking on Azure exposes a new SRIOV interface to the VM. # This interface is transparentlybonded to the synthetic interface, # so NetworkManager should just ignore any SRIOV interfaces. SUBSYSTEM=="net", DRIVERS=="hv_pci", ACTION!="remove", ENV{NM_UNMANAGED}="1" EOF
Ensure that the network service starts at boot time:
sudo chkconfig network on
Register your Red Hat subscription to enable the installation of packages from the RHEL repository:
sudo subscription-manager register --auto-attach --username=XXX --password=XXX
The WALinuxAgent package,
WALinuxAgent-<version>
, has been pushed to the Red Hat extras repository. Enable the extras repository:sudo subscription-manager repos --enable=rhel-6-server-extras-rpms
Modify the kernel boot line in your grub configuration to include more kernel parameters for Azure. To do this modification, open
/boot/grub/menu.lst
in a text editor. Ensure that the default kernel includes the following parameters:console=ttyS0 earlyprintk=ttyS0
This action also ensures that all console messages are sent to the first serial port, which can assist Azure support with debugging issues.
We also recommend that you remove the following parameters:
rhgb quiet crashkernel=auto
Graphical and quiet boots aren't useful in a cloud environment where you want all the logs to be sent to the serial port. You can leave the
crashkernel
option configured if you want. This parameter reduces the amount of available memory in the VM by 128 MB or more. This configuration might be a problem for smaller VM sizes.Ensure that the secure shell (SSH) server is installed and configured to start at boot time, which is usually the default. Modify
/etc/ssh/sshd_config
to include the following line:ClientAliveInterval 180
Install the Azure Linux agent:
sudo yum install WALinuxAgent sudo chkconfig waagent on
Installing the WALinuxAgent package removes the
NetworkManager
andNetworkManager-gnome
packages if they weren't already removed in step 3.Don't create swap space on the operating system disk.
The Azure Linux agent can automatically configure swap space by using the local resource disk that's attached to the VM after the VM is provisioned on Azure. The local resource disk is a temporary disk and it might be emptied if the VM is deprovisioned. After you install the Azure Linux agent in the previous step, modify the following parameters in
/etc/waagent.conf
appropriately:ResourceDisk.Format=y ResourceDisk.Filesystem=ext4 ResourceDisk.MountPoint=/mnt/resource ResourceDisk.EnableSwap=y ResourceDisk.SwapSizeMB=2048 ## NOTE: set this to whatever you need it to be.
Unregister the subscription (if necessary):
sudo subscription-manager unregister
Deprovision the VM and prepare it for provisioning on Azure:
Note
If you're migrating a specific VM and don't want to create a generalized image, skip the deprovision step.
sudo waagent -force -deprovision sudo export HISTSIZE=0
Select Action > Shut Down in Hyper-V Manager. Your Linux VHD is now ready to be uploaded to Azure.
RHEL 7 using Hyper-V Manager
In Hyper-V Manager, select the VM.
Select Connect to open a console window for the VM.
Create or edit the
/etc/sysconfig/network
file, and add the following text:NETWORKING=yes HOSTNAME=localhost.localdomain
Create or edit the
/etc/sysconfig/network-scripts/ifcfg-eth0
file, and add the following text:DEVICE=eth0 ONBOOT=yes BOOTPROTO=dhcp TYPE=Ethernet USERCTL=no PEERDNS=yes IPV6INIT=no PERSISTENT_DHCLIENT=yes NM_CONTROLLED=yes
Note
When you use Accelerated Networking, the synthetic interface that's created must be configured to be unmanaged by using a udev rule. This action prevents
NetworkManager
from assigning the same IP to it as the primary interface.To apply it:
sudo cat <<EOF>> /etc/udev/rules.d/68-azure-sriov-nm-unmanaged.rules # Accelerated Networking on Azure exposes a new SRIOV interface to the VM. # This interface is transparentlybonded to the synthetic interface, # so NetworkManager should just ignore any SRIOV interfaces. SUBSYSTEM=="net", DRIVERS=="hv_pci", ACTION!="remove", ENV{NM_UNMANAGED}="1" EOF
Ensure that the network service starts at boot time:
sudo systemctl enable network
Register your Red Hat subscription to enable the installation of packages from the RHEL repository:
sudo subscription-manager register --auto-attach --username=XXX --password=XXX
Modify the kernel boot line in your grub configuration to include more kernel parameters for Azure. To do this modification, open
/etc/default/grub
in a text editor and edit theGRUB_CMDLINE_LINUX
parameter. For example:GRUB_CMDLINE_LINUX="console=tty1 console=ttyS0,115200n8 earlyprintk=ttyS0 net.ifnames=0" GRUB_TERMINAL_OUTPUT="serial console" GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1" ENABLE_BLSCFG=true
Note
If ENABLE_BLSCFG=false is present in
/etc/default/grub
instead ofENABLE_BLSCFG=true
, tools such as grubedit or gubby, which rely on the Boot Loader Specification (BLS) for managing boot entries and configurations, might not function correctly in RHEL 8 and 9. IfENABLE_BLSCFG
isn't present, the default behavior isfalse
.This modification also ensures that all console messages are sent to the first serial port and enable interaction with the serial console, which can assist Azure support with debugging issues. This configuration also turns off the new RHEL 7 naming conventions for network interface cards (NICs).
rhgb quiet crashkernel=auto
Graphical and quiet boots aren't useful in a cloud environment where you want all the logs to be sent to the serial port. You can leave the
crashkernel
option configured if you want. This parameter reduces the amount of available memory in the VM by 128 MB or more, which might be a problem for smaller VM sizes.After you're finished editing
/etc/default/grub
, run the following command to rebuild the grub configuration:sudo grub2-mkconfig -o /boot/grub2/grub.cfg
Note
If you're uploading a UEFI-enabled VM, the command to update grub is
grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
.Ensure that the SSH server is installed and configured to start at boot time, which is usually the default. Modify
/etc/ssh/sshd_config
to include the following line:ClientAliveInterval 180
The WALinuxAgent package,
WALinuxAgent-<version>
, has been pushed to the Red Hat extras repository. Enable the extras repository:sudo subscription-manager repos --enable=rhel-7-server-extras-rpms
Install the Azure Linux agent,
cloud-init
, and other necessary utilities:sudo yum install -y WALinuxAgent cloud-init cloud-utils-growpart gdisk hyperv-daemons sudo systemctl enable waagent.service sudo systemctl enable cloud-init.service
Configure
cloud-init
to handle the provisioning:Configure
waagent
forcloud-init
:sudo sed -i 's/Provisioning.Agent=auto/Provisioning.Agent=auto/g' /etc/waagent.conf sudo sed -i 's/ResourceDisk.Format=y/ResourceDisk.Format=n/g' /etc/waagent.conf sudo sed -i 's/ResourceDisk.EnableSwap=y/ResourceDisk.EnableSwap=n/g' /etc/waagent.conf
Note
If you're migrating a specific VM and don't want to create a generalized image, set
Provisioning.Agent=disabled
on the/etc/waagent.conf
configuration.Configure mounts:
sudo echo "Adding mounts and disk_setup to init stage" sudo sed -i '/ - mounts/d' /etc/cloud/cloud.cfg sudo sed -i '/ - disk_setup/d' /etc/cloud/cloud.cfg sudo sed -i '/cloud_init_modules/a\\ - mounts' /etc/cloud/cloud.cfg sudo sed -i '/cloud_init_modules/a\\ - disk_setup' /etc/cloud/cloud.cfg
Configure the Azure data source:
sudo echo "Allow only Azure datasource, disable fetching network setting via IMDS" sudo cat > /etc/cloud/cloud.cfg.d/91-azure_datasource.cfg <<EOF datasource_list: [ Azure ] datasource: Azure: apply_network_config: False EOF
If configured, remove the existing swap file:
if [[ -f /mnt/resource/swapfile ]]; then echo "Removing swapfile" #RHEL uses a swapfile by default swapoff /mnt/resource/swapfile rm /mnt/resource/swapfile -f fi
Configure
cloud-init
logging:sudo echo "Add console log file" sudo cat >> /etc/cloud/cloud.cfg.d/05_logging.cfg <<EOF # This tells cloud-init to redirect its stdout and stderr to # 'tee -a /var/log/cloud-init-output.log' so the user can see output # there without needing to look on the console. output: {all: '| tee -a /var/log/cloud-init-output.log'} EOF
Swap configuration:
Don't create swap space on the operating system disk.
Previously, the Azure Linux agent was used to automatically configure swap space by using the local resource disk that's attached to the VM after the VM is provisioned on Azure. This action is now handled by
cloud-init
. You must not use the Linux agent to format the resource disk to create the swap file. Modify the following parameters in/etc/waagent.conf
appropriately:ResourceDisk.Format=n ResourceDisk.EnableSwap=n
If you want to mount, format, and create the swap, you can either:
Pass this code in as a
cloud-init
configuration every time you create a VM through custom data. We recommend this method.Use a
cloud-init
directive baked into the image that does this step every time the VM is created.sudo echo 'DefaultEnvironment="CLOUD_CFG=/etc/cloud/cloud.cfg.d/00-azure-swap.cfg"' >> /etc/systemd/system.conf sudo cat > /etc/cloud/cloud.cfg.d/00-azure-swap.cfg << EOF #cloud-config # Generated by Azure cloud image build disk_setup: ephemeral0: table_type: mbr layout: [66, [33, 82]] overwrite: True fs_setup: - device: ephemeral0.1 filesystem: ext4 - device: ephemeral0.2 filesystem: swap mounts: - ["ephemeral0.1", "/mnt/resource"] - ["ephemeral0.2", "none", "swap", "sw,nofail,x-systemd.requires=cloud-init.service,x-systemd.device-timeout=2", "0", "0"] EOF
If you want to unregister the subscription, run the following command:
sudo subscription-manager unregister
Deprovision the VM and prepare it for provisioning on Azure:
Caution
If you're migrating a specific VM and don't want to create a generalized image, skip the deprovision step. Running the command
waagent -force -deprovision+user
renders the source machine unusable. This step is intended only to create a generalized image.sudo rm -f /var/log/waagent.log sudo cloud-init clean sudo waagent -force -deprovision+user sudo rm -f ~/.bash_history sudo export HISTSIZE=0
Select Action > Shut Down in Hyper-V Manager. Your Linux VHD is now ready to be uploaded to Azure.
RHEL 8+ using Hyper-V Manager
In Hyper-V Manager, select the VM.
Select Connect to open a console window for the VM.
Ensure that the Network Manager service starts at boot time:
sudo systemctl enable NetworkManager.service
Configure the network interface to automatically start at boot and use the Dynamic Host Configuration Protocol:
sudo nmcli con mod eth0 connection.autoconnect yes ipv4.method auto
Note
When you use Accelerated Networking, the synthetic interface that's created must be configured to be unmanaged by using a udev rule. This action prevents
NetworkManager
from assigning the same IP to it as the primary interface.To apply it:
sudo cat <<EOF>> /etc/udev/rules.d/68-azure-sriov-nm-unmanaged.rules # Accelerated Networking on Azure exposes a new SRIOV interface to the VM. # This interface is transparentlybonded to the synthetic interface, # so NetworkManager should just ignore any SRIOV interfaces. SUBSYSTEM=="net", DRIVERS=="hv_pci", ACTION!="remove", ENV{NM_UNMANAGED}="1" EOF
Register your Red Hat subscription to enable the installation of packages from the RHEL repository:
sudo subscription-manager register --auto-attach --username=XXX --password=XXX
Modify the kernel boot line in your grub configuration to include more kernel parameters for Azure and enable the serial console.
Remove current GRUB parameters:
sudo grub2-editenv - unset kernelopts
Edit
/etc/default/grub
in a text editor, and add the following parameters:GRUB_CMDLINE_LINUX="console=tty1 console=ttyS0,115200n8 earlyprintk=ttyS0,115200 earlyprintk=ttyS0 net.ifnames=0" GRUB_TERMINAL_OUTPUT="serial console" GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"
This modification also ensures that all console messages are sent to the first serial port and enable interaction with the serial console, which can assist Azure support with debugging issues. This configuration also turns off the new naming conventions for NICs.
We recommend that you also remove the following parameters:
rhgb quiet crashkernel=auto
Graphical and quiet boots aren't useful in a cloud environment where you want all the logs to be sent to the serial port. You can leave the
crashkernel
option configured if you want. This parameter reduces the amount of available memory in the VM by 128 MB or more, which might be a problem for smaller VM sizes.After you're finished editing
/etc/default/grub
, run the following command to rebuild the grub configuration:sudo grub2-mkconfig -o /boot/grub2/grub.cfg
For a UEFI-enabled VM, run the following command:
sudo grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
Ensure that the SSH server is installed and configured to start at boot time, which is usually the default. Modify
/etc/ssh/sshd_config
to include the following line:ClientAliveInterval 180
Install the Azure Linux agent,
cloud-init
, and other necessary utilities:sudo yum install -y WALinuxAgent cloud-init cloud-utils-growpart gdisk hyperv-daemons sudo systemctl enable waagent.service sudo systemctl enable cloud-init.service
Configure
cloud-init
to handle the provisioning:Configure
waagent
forcloud-init
:sudo sed -i 's/Provisioning.Agent=auto/Provisioning.Agent=cloud-init/g' /etc/waagent.conf sudo sed -i 's/ResourceDisk.Format=y/ResourceDisk.Format=n/g' /etc/waagent.conf sudo sed -i 's/ResourceDisk.EnableSwap=y/ResourceDisk.EnableSwap=n/g' /etc/waagent.conf
Note
If you're migrating a specific VM and don't want to create a generalized image, set
Provisioning.Agent=disabled
on the/etc/waagent.conf
configuration.Configure mounts:
sudo echo "Adding mounts and disk_setup to init stage" sudo sed -i '/ - mounts/d' /etc/cloud/cloud.cfg sudo sed -i '/ - disk_setup/d' /etc/cloud/cloud.cfg sudo sed -i '/cloud_init_modules/a\\ - mounts' /etc/cloud/cloud.cfg sudo sed -i '/cloud_init_modules/a\\ - disk_setup' /etc/cloud/cloud.cfg
Configure the Azure data source:
sudo echo "Allow only Azure datasource, disable fetching network setting via IMDS" sudo cat > /etc/cloud/cloud.cfg.d/91-azure_datasource.cfg <<EOF datasource_list: [ Azure ] datasource: Azure: apply_network_config: False EOF
If configured, remove the existing swap file:
if [[ -f /mnt/resource/swapfile ]]; then echo "Removing swapfile" #RHEL uses a swapfile by defaul swapoff /mnt/resource/swapfile rm /mnt/resource/swapfile -f fi
Configure
cloud-init
logging:sudo echo "Add console log file" sudo cat >> /etc/cloud/cloud.cfg.d/05_logging.cfg <<EOF # This tells cloud-init to redirect its stdout and stderr to # 'tee -a /var/log/cloud-init-output.log' so the user can see output # there without needing to look on the console. output: {all: '| tee -a /var/log/cloud-init-output.log'} EOF
Swap configuration:
Don't create swap space on the operating system disk.
Previously, the Azure Linux agent was used to automatically configure swap space by using the local resource disk that's attached to the VM after the VM is provisioned on Azure. This action is now handled by
cloud-init
. You must not use the Linux agent to format the resource disk create the swap file. Modify the following parameters in/etc/waagent.conf
appropriately:ResourceDisk.Format=n ResourceDisk.EnableSwap=n
Pass this code in as a
cloud-init
configuration every time you create a VM through custom data. We recommend this method.Use a
cloud-init
directive baked into the image that does this step every time the VM is created.sudo echo 'DefaultEnvironment="CLOUD_CFG=/etc/cloud/cloud.cfg.d/00-azure-swap.cfg"' >> /etc/systemd/system.conf sudo cat > /etc/cloud/cloud.cfg.d/00-azure-swap.cfg << EOF #cloud-config # Generated by Azure cloud image build disk_setup: ephemeral0: table_type: mbr layout: [66, [33, 82]] overwrite: True fs_setup: - device: ephemeral0.1 filesystem: ext4 - device: ephemeral0.2 filesystem: swap mounts: - ["ephemeral0.1", "/mnt/resource"] - ["ephemeral0.2", "none", "swap", "sw,nofail,x-systemd.device-timeout=2,x-systemd.requires=cloud-init.service", "0", "0"] EOF
If you want to unregister the subscription, run the following command:
sudo subscription-manager unregister
Run the following commands to deprovision the VM and prepare it for provisioning on Azure:
sudo cloud-init clean sudo waagent -force -deprovision+user sudo rm -f ~/.bash_history sudo sudo rm -f /var/log/waagent.log sudo export HISTSIZE=0
Caution
If you're migrating a specific VM and don't want to create a generalized image, skip the deprovision step. Running the command
waagent -force -deprovision+user
renders the source machine unusable. This step is intended only to create a generalized image.Select Action > Shut Down in Hyper-V Manager. Your Linux VHD is now ready to be uploaded to Azure.
KVM
This section shows you how to use KVM to prepare a RHEL 6 or RHEL 7 distro to upload to Azure.
RHEL 6 using KVM
Important
On November 30, 2020, RHEL 6 reached the end of the Maintenance phase. The Maintenance phase is followed by the Extended Life phase. As RHEL 6 transitions out of the Full/Maintenance phases, we strongly recommend that you upgrade to RHEL 7, 8, or 9. If you must stay on RHEL 6, we recommend that you add the RHEL Extended Life Cycle Support Add-on.
Download the KVM image of RHEL 6 from the Red Hat website.
Set a root password.
Generate an encrypted password, and copy the output of the command:
sudo openssl passwd -1 changeme
Set a root password with guestfish:
sudo guestfish --rw -a <image-name> > <fs> run > <fs> list-filesystems > <fs> mount /dev/sda1 / > <fs> vi /etc/shadow > <fs> exit
Change the second field of the root user from
!!
to the encrypted password.Create a VM in KVM from the qcow2 image. Set the disk type to qcow2, and set the virtual network interface device model to virtio. Then, start the VM and sign in as root.
Create or edit the
/etc/sysconfig/network
file, and add the following text:NETWORKING=yes HOSTNAME=localhost.localdomain
Create or edit the
/etc/sysconfig/network-scripts/ifcfg-eth0
file, and add the following text:DEVICE=eth0 ONBOOT=yes BOOTPROTO=dhcp TYPE=Ethernet USERCTL=no PEERDNS=yes IPV6INIT=no
Move (or remove) the udev rules to avoid generating static rules for the Ethernet interface. These rules cause problems when you clone a VM in Azure or Hyper-V:
sudo ln -s /dev/null /etc/udev/rules.d/75-persistent-net-generator.rules sudo rm -f /etc/udev/rules.d/70-persistent-net.rules
Note
When you use Accelerated Networking, the synthetic interface that's created must be configured to be unmanaged by using a udev rule. This action prevents
NetworkManager
from assigning the same IP to it as the primary interface.To apply it:
sudo cat <<EOF>> /etc/udev/rules.d/68-azure-sriov-nm-unmanaged.rules # Accelerated Networking on Azure exposes a new SRIOV interface to the VM. # This interface is transparently bonded to the synthetic interface, # so NetworkManager should just ignore any SRIOV interfaces. SUBSYSTEM=="net", DRIVERS=="hv_pci", ACTION!="remove", ENV{NM_UNMANAGED}="1" EOF
Ensure that the network service starts at boot time:
sudo chkconfig network on
Register your Red Hat subscription to enable the installation of packages from the RHEL repository:
sudo subscription-manager register --auto-attach --username=XXX --password=XXX
Modify the kernel boot line in your grub configuration to include more kernel parameters for Azure. To do this configuration, open
/boot/grub/menu.lst
in a text editor. Ensure that the default kernel includes the following parameters:console=ttyS0 earlyprintk=ttyS0
This step also ensures that all console messages are sent to the first serial port, which can assist Azure support with debugging issues.
We also recommend that you remove the following parameters:
rhgb quiet crashkernel=auto
Graphical and quiet boots aren't useful in a cloud environment where you want all the logs to be sent to the serial port. You can leave the
crashkernel
option configured if you want. This parameter reduces the amount of available memory in the VM by 128 MB or more, which might be a problem for smaller VM sizes.Add Hyper-V modules to initramfs:
Edit
/etc/dracut.conf
, and add the following content:add_drivers+=" hv_vmbus hv_netvsc hv_storvsc "
Rebuild initramfs:
sudo dracut -f -v
Uninstall
cloud-init
:sudo yum remove cloud-init
Ensure that the SSH server is installed and configured to start at boot time:
sudo chkconfig sshd on
Modify
/etc/ssh/sshd_config
to include the following lines:PasswordAuthentication yes ClientAliveInterval 180
The WALinuxAgent package,
WALinuxAgent-<version>
, has been pushed to the Red Hat extras repository. Enable the extras repository:sudo subscription-manager repos --enable=rhel-6-server-extras-rpms
Install the Azure Linux agent:
sudo yum install WALinuxAgent sudo chkconfig waagent on
The Azure Linux agent can automatically configure swap space by using the local resource disk that's attached to the VM after the VM is provisioned on Azure. The local resource disk is a temporary disk, and it might be emptied if the VM is deprovisioned. After you install the Azure Linux agent in the previous step, modify the following parameters in
/etc/waagent.conf
appropriately:ResourceDisk.Format=y ResourceDisk.Filesystem=ext4 ResourceDisk.MountPoint=/mnt/resource ResourceDisk.EnableSwap=y ResourceDisk.SwapSizeMB=2048 ## NOTE: set this to whatever you need it to be.
Unregister the subscription (if necessary):
sudo subscription-manager unregister
Run the following commands to deprovision the VM and prepare it for provisioning on Azure.
Note
If you're migrating a specific VM and don't want to create a generalized image, skip the deprovision step.
sudo rm -rf /var/lib/waagent/ sudo rm -f /var/log/waagent.log sudo waagent -force -deprovision+user sudo rm -f ~/.bash_history sudo export HISTSIZE=0
Shut down the VM in KVM.
Convert the qcow2 image to the VHD format.
Note
There's a known bug in qemu-img versions >=2.2.1 that results in an improperly formatted VHD. The issue has been fixed in QEMU 2.6. We recommend that you use either qemu-img 2.2.0 or lower, or update to 2.6 or higher. For more information, see this website .
First convert the image to raw format:
sudo qemu-img convert -f qcow2 -O raw rhel-6.9.qcow2 rhel-6.9.raw
Make sure that the size of the raw image is aligned with 1 MB. Otherwise, round up the size to align with 1 MB:
MB=$((1024*1024)) size=$(qemu-img info -f raw --output json "rhel-6.9.raw" | \ gawk 'match($0, /"virtual-size": ([0-9]+),/, val) {print val[1]}') rounded_size=$((($size/$MB + 1)*$MB)) sudo qemu-img resize rhel-6.9.raw $rounded_size
Convert the raw disk to a fixed-size VHD:
sudo qemu-img convert -f raw -o subformat=fixed -O vpc rhel-6.9.raw rhel-6.9.vhd
Or, with qemu version 2.6+, include the
force_size
option:sudo qemu-img convert -f raw -o subformat=fixed,force_size -O vpc rhel-6.9.raw rhel-6.9.vhd
RHEL 7 using KVM
Download the KVM image of RHEL 7 from the Red Hat website. This procedure uses RHEL 7 as an example.
Set a root password.
Generate an encrypted password, and copy the output of the command:
sudo openssl passwd -1 changeme
Set a root password with guestfish:
sudo guestfish --rw -a <image-name> > <fs> run > <fs> list-filesystems > <fs> mount /dev/sda1 / > <fs> vi /etc/shadow > <fs> exit
Change the second field of root user from
!!
to the encrypted password.Create a VM in KVM from the qcow2 image. Set the disk type to qcow2, and set the virtual network interface device model to virtio. Then, start the VM and sign in as root.
Create or edit the
/etc/sysconfig/network
file, and add the following text:NETWORKING=yes HOSTNAME=localhost.localdomain
Create or edit the
/etc/sysconfig/network-scripts/ifcfg-eth0
file, and add the following text:DEVICE=eth0 ONBOOT=yes BOOTPROTO=dhcp TYPE=Ethernet USERCTL=no PEERDNS=yes IPV6INIT=no PERSISTENT_DHCLIENT=yes NM_CONTROLLED=yes
Note
When you use Accelerated Networking, the synthetic interface that's created must be configured to be unmanaged by using a udev rule. This action prevents
NetworkManager
from assigning the same IP to it as the primary interface.To apply it:
sudo cat <<EOF>> /etc/udev/rules.d/68-azure-sriov-nm-unmanaged.rules # Accelerated Networking on Azure exposes a new SRIOV interface to the VM. # This interface is transparentlybonded to the synthetic interface, # so NetworkManager should just ignore any SRIOV interfaces. SUBSYSTEM=="net", DRIVERS=="hv_pci", ACTION!="remove", ENV{NM_UNMANAGED}="1" EOF
Ensure that the network service starts at boot time:
sudo systemctl enable network
Register your Red Hat subscription to enable installation of packages from the RHEL repository:
sudo subscription-manager register --auto-attach --username=XXX --password=XXX
Modify the kernel boot line in your grub configuration to include more kernel parameters for Azure. To do this configuration, open
/etc/default/grub
in a text editor and edit theGRUB_CMDLINE_LINUX
parameter. For example:GRUB_CMDLINE_LINUX="console=ttyS0 earlyprintk=ttyS0 net.ifnames=0"
This command also ensures that all console messages are sent to the first serial port, which can assist Azure support with debugging issues. The command also turns off the new RHEL 7 naming conventions for NICs. We also recommend that you remove the following parameters:
rhgb quiet crashkernel=auto
Graphical and quiet boots aren't useful in a cloud environment where you want all the logs to be sent to the serial port. You can leave the
crashkernel
option configured if you want. This parameter reduces the amount of available memory in the VM by 128 MB or more, which might be a problem for smaller VM sizes.After you're finished editing
/etc/default/grub
, run the following command to rebuild the grub configuration:sudo grub2-mkconfig -o /boot/grub2/grub.cfg
Add Hyper-V modules into initramfs.
Edit
/etc/dracut.conf
and add content:add_drivers+=" hv_vmbus hv_netvsc hv_storvsc "
Rebuild initramfs:
sudo dracut -f -v
Uninstall
cloud-init
:sudo yum remove cloud-init
Ensure that the SSH server is installed and configured to start at boot time:
sudo systemctl enable sshd
Modify
/etc/ssh/sshd_config
to include the following lines:PasswordAuthentication yes ClientAliveInterval 180
The WALinuxAgent package,
WALinuxAgent-<version>
, has been pushed to the Red Hat extras repository. Enable the extras repository:sudo subscription-manager repos --enable=rhel-7-server-extras-rpms
Install the Azure Linux agent:
sudo yum install WALinuxAgent
Enable the
waagent
service:sudo systemctl enable waagent.service
Install
cloud-init
.Follow the steps in "Prepare a RHEL 7 VM from Hyper-V Manager," step 12, "Install
cloud-init
to handle the provisioning."Swap configuration:
- Don't create swap space on the operating system disk.
- Follow the steps in "Prepare a RHEL 7 VM from Hyper-V Manager," step 13, "Swap configuration."
Unregister the subscription (if necessary):
sudo subscription-manager unregister
Deprovision by following the steps in "Prepare a RHEL 7 VM from Hyper-V Manager," step 15, "Deprovision."
Shut down the VM in KVM.
Convert the qcow2 image to the VHD format.
Note
There's a known bug in qemu-img versions >=1.1.1 that results in an improperly formatted VHD. The issue has been fixed in QEMU 1.6. We recommend that you use either qemu-img 1.1.0 or lower, or update to 1.6 or higher. For more information, see this website.
First convert the image to raw format:
sudo qemu-img convert -f qcow2 -O raw rhel-7.4.qcow2 rhel-7.4.raw
Make sure that the size of the raw image is aligned with 1 MB. Otherwise, round up the size to align with 1 MB:
MB=$((1024*1024)) size=$(qemu-img info -f raw --output json "rhel-7.4.raw" | \ gawk 'match($0, /"virtual-size": ([0-9]+),/, val) {print val[1]}') rounded_size=$((($size/$MB + 1)*$MB)) sudo qemu-img resize rhel-7.4.raw $rounded_size
Convert the raw disk to a fixed-size VHD:
sudo qemu-img convert -f raw -o subformat=fixed -O vpc rhel-7.4.raw rhel-7.4.vhd
Or, with qemu version 1.6+, include the
force_size
option:sudo qemu-img convert -f raw -o subformat=fixed,force_size -O vpc rhel-7.4.raw rhel-7.4.vhd
VMware
This section shows you how to prepare a RHEL 6 or RHEL 7 distro from VMware.
Prerequisites
This section assumes that you've already installed a RHEL VM in VMware. For information about how to install an operating system in VMware, see the VMware Guest Operating System Installation Guide.
- When you install the Linux operating system, we recommend that you use standard partitions rather than LVM, which is often the default for many installations. Using partitions avoids LVM name conflicts with a cloned VM, particularly if an operating system disk ever needs to be attached to another VM for troubleshooting. LVM or RAID can be used on data disks if you want.
- Don't configure a swap partition on the operating system disk. You can configure the Linux agent to create a swap file on the temporary resource disk. For more information, read the following steps.
- When you create the VHD, select Store virtual disk as a single file.
RHEL 6 using VMware
Important
On November 30, 2020, RHEL 6 reached the end of the Maintenance phase. The Maintenance phase is followed by the Extended Life phase. As RHEL 6 transitions out of the Full/Maintenance phases, we strongly recommend that you upgrade to RHEL 7 or 8 or 9. If you must stay on RHEL 6, we recommend that you add the RHEL Extended Life Cycle Support Add-on.
In RHEL 6,
NetworkManager
can interfere with the Azure Linux agent. Uninstall this package:sudo rpm -e --nodeps NetworkManager
Create a file named network in the
/etc/sysconfig/
directory that contains the following text:NETWORKING=yes HOSTNAME=localhost.localdomain
Create or edit the
/etc/sysconfig/network-scripts/ifcfg-eth0
file, and add the following text:DEVICE=eth0 ONBOOT=yes BOOTPROTO=dhcp TYPE=Ethernet USERCTL=no PEERDNS=yes IPV6INIT=no
Move (or remove) the udev rules to avoid generating static rules for the Ethernet interface. These rules cause problems when you clone a VM in Azure or Hyper-V:
sudo ln -s /dev/null /etc/udev/rules.d/75-persistent-net-generator.rules sudo rm -f /etc/udev/rules.d/70-persistent-net.rules
Note
When you use Accelerated Networking, the synthetic interface that's created must be configured to be unmanaged by using a udev rule. This action prevents
NetworkManager
from assigning the same IP to it as the primary interface.To apply it:
sudo cat <<EOF>> /etc/udev/rules.d/68-azure-sriov-nm-unmanaged.rules # Accelerated Networking on Azure exposes a new SRIOV interface to the VM. # This interface is transparently bonded to the synthetic interface, # so NetworkManager should just ignore any SRIOV interfaces. SUBSYSTEM=="net", DRIVERS=="hv_pci", ACTION!="remove", ENV{NM_UNMANAGED}="1" EOF
Ensure that the network service starts at boot time:
sudo chkconfig network on
Register your Red Hat subscription to enable the installation of packages from the RHEL repository:
sudo subscription-manager register --auto-attach --username=XXX --password=XXX
The WALinuxAgent package,
WALinuxAgent-<version>
, has been pushed to the Red Hat extras repository. Enable the extras repository:sudo subscription-manager repos --enable=rhel-6-server-extras-rpms
Modify the kernel boot line in your grub configuration to include more kernel parameters for Azure. To do this step, open
/etc/default/grub
in a text editor and edit theGRUB_CMDLINE_LINUX
parameter. For example:GRUB_CMDLINE_LINUX="console=ttyS0 earlyprintk=ttyS0"
This step also ensures that all console messages are sent to the first serial port, which can assist Azure support with debugging issues. We also recommend that you remove the following parameters:
rhgb quiet crashkernel=auto
Graphical and quiet boots aren't useful in a cloud environment where you want all the logs to be sent to the serial port. You can leave the
crashkernel
option configured if you want. This parameter reduces the amount of available memory in the VM by 128 MB or more, which might be a problem for smaller VM sizes.Add Hyper-V modules to initramfs:
Edit
/etc/dracut.conf
, and add the following content:add_drivers+=" hv_vmbus hv_netvsc hv_storvsc "
Rebuild initramfs:
sudo dracut -f -v
Ensure that the SSH server is installed and configured to start at boot time, which is usually the default. Modify
/etc/ssh/sshd_config
to include the following line:ClientAliveInterval 180
Install the Azure Linux agent:
sudo yum install WALinuxAgent sudo chkconfig waagent on
Don't create a swap space on the operating system disk.
The Azure Linux agent can automatically configure swap space by using the local resource disk that's attached to the VM after the VM is provisioned on Azure. The local resource disk is a temporary disk, and it might be emptied if the VM is deprovisioned. After you install the Azure Linux agent in the previous step, modify the following parameters in
/etc/waagent.conf
appropriately:ResourceDisk.Format=y ResourceDisk.Filesystem=ext4 ResourceDisk.MountPoint=/mnt/resource ResourceDisk.EnableSwap=y ResourceDisk.SwapSizeMB=2048 ## NOTE: set this to whatever you need it to be.
Unregister the subscription (if necessary):
sudo subscription-manager unregister
Run the following commands to deprovision the VM and prepare it for provisioning on Azure:
Note
If you're migrating a specific VM and don't want to create a generalized image, skip the deprovision step.
sudo rm -rf /var/lib/waagent/ sudo rm -f /var/log/waagent.log sudo waagent -force -deprovision+user sudo rm -f ~/.bash_history sudo export HISTSIZE=0
Shut down the VM, and convert the VMDK file to a .vhd file.
Note
There's a known bug in qemu-img versions >=2.2.1 that results in an improperly formatted VHD. The issue has been fixed in QEMU 2.6. We recommend that you use either qemu-img 2.2.0 or lower, or update to 2.6 or higher. For more information, see this website.
First convert the image to raw format:
sudo qemu-img convert -f vmdk -O raw rhel-6.9.vmdk rhel-6.9.raw
Make sure that the size of the raw image is aligned with 1 MB. Otherwise, round up the size to align with 1 MB:
MB=$((1024*1024)) size=$(qemu-img info -f raw --output json "rhel-6.9.raw" | \ gawk 'match($0, /"virtual-size": ([0-9]+),/, val) {print val[1]}') rounded_size=$((($size/$MB + 1)*$MB)) sudo qemu-img resize rhel-6.9.raw $rounded_size
Convert the raw disk to a fixed-size VHD:
sudo qemu-img convert -f raw -o subformat=fixed -O vpc rhel-6.9.raw rhel-6.9.vhd
Or, with qemu version 2.6+, include the
force_size
option:sudo qemu-img convert -f raw -o subformat=fixed,force_size -O vpc rhel-6.9.raw rhel-6.9.vhd
RHEL 7 using VMware
Create or edit the
/etc/sysconfig/network
file, and add the following text:NETWORKING=yes HOSTNAME=localhost.localdomain
Create or edit the
/etc/sysconfig/network-scripts/ifcfg-eth0
file, and add the following text:DEVICE=eth0 ONBOOT=yes BOOTPROTO=dhcp TYPE=Ethernet USERCTL=no PEERDNS=yes IPV6INIT=no PERSISTENT_DHCLIENT=yes NM_CONTROLLED=yes
Note
When you use Accelerated Networking, the synthetic interface that's created must be configured to be unmanaged by using a udev rule. This action prevents
NetworkManager
from assigning the same IP to it as the primary interface.To apply it:
sudo cat <<EOF>> /etc/udev/rules.d/68-azure-sriov-nm-unmanaged.rules # Accelerated Networking on Azure exposes a new SRIOV interface to the VM. # This interface is transparentlybonded to the synthetic interface, # so NetworkManager should just ignore any SRIOV interfaces. SUBSYSTEM=="net", DRIVERS=="hv_pci", ACTION!="remove", ENV{NM_UNMANAGED}="1" EOF
Ensure that the network service starts at boot time:
sudo systemctl enable network
Register your Red Hat subscription to enable the installation of packages from the RHEL repository:
sudo subscription-manager register --auto-attach --username=XXX --password=XXX
Modify the kernel boot line in your grub configuration to include more kernel parameters for Azure. To do this modification, open
/etc/default/grub
in a text editor and edit theGRUB_CMDLINE_LINUX
parameter. For example:GRUB_CMDLINE_LINUX="console=ttyS0 earlyprintk=ttyS0 net.ifnames=0"
This configuration also ensures that all console messages are sent to the first serial port, which can assist Azure support with debugging issues. It also turns off the new RHEL 7 naming conventions for NICs. In addition, we recommend that you remove the following parameters:
rhgb quiet crashkernel=auto
Graphical and quiet boots aren't useful in a cloud environment where you want all the logs to be sent to the serial port. You can leave the
crashkernel
option configured if you want. This parameter reduces the amount of available memory in the VM by 128 MB or more, which might be a problem for smaller VM sizes.After you're finished editing
/etc/default/grub
, run the following command to rebuild the grub configuration:sudo grub2-mkconfig -o /boot/grub2/grub.cfg
Add Hyper-V modules to initramfs:
Edit
/etc/dracut.conf
, add content:add_drivers+=" hv_vmbus hv_netvsc hv_storvsc "
Rebuild initramfs:
sudo dracut -f -v
Ensure that the SSH server is installed and configured to start at boot time. This setting is usually the default. Modify
/etc/ssh/sshd_config
to include the following line:ClientAliveInterval 180
The WALinuxAgent package,
WALinuxAgent-<version>
, has been pushed to the Red Hat extras repository. Enable the extras repository:sudo subscription-manager repos --enable=rhel-7-server-extras-rpms
Install the Azure Linux agent:
sudo yum install WALinuxAgent sudo systemctl enable waagent.service
Install
cloud-init
:Follow the steps in "Prepare a RHEL 7 VM from Hyper-V Manager," step 12, "Install
cloud-init
to handle the provisioning."Swap configuration:
- Don't create swap space on the operating system disk.
- Follow the steps in "Prepare a RHEL 7 VM from Hyper-V Manager," step 13, "Swap configuration."
If you want to unregister the subscription, run the following command:
sudo subscription-manager unregister
Deprovision by following the steps in "Prepare a RHEL 7 VM from Hyper-V Manager," step 15, "Deprovision."
Shut down the VM and convert the VMDK file to the VHD format.
Note
There's a known bug in qemu-img versions >=2.2.1 that results in an improperly formatted VHD. The issue has been fixed in QEMU 2.6. We recommend that you use either qemu-img 2.2.0 or lower, or update to 2.6 or higher. For more information, see this website.
First convert the image to raw format:
sudo qemu-img convert -f vmdk -O raw rhel-7.4.vmdk rhel-7.4.raw
Make sure that the size of the raw image is aligned with 1 MB. Otherwise, round up the size to align with 1 MB:
MB=$((1024*1024)) size=$(qemu-img info -f raw --output json "rhel-7.4.raw" | \ gawk 'match($0, /"virtual-size": ([0-9]+),/, val) {print val[1]}') rounded_size=$((($size/$MB + 1)*$MB)) sudo qemu-img resize rhel-7.4.raw $rounded_size
Convert the raw disk to a fixed-size VHD:
sudo qemu-img convert -f raw -o subformat=fixed -O vpc rhel-7.4.raw rhel-7.4.vhd
Or, with qemu version 2.6+, include the
force_size
option:sudo qemu-img convert -f raw -o subformat=fixed,force_size -O vpc rhel-7.4.raw rhel-7.4.vhd
Kickstart file
This section shows you how to prepare a RHEL 7 distro from an ISO by using a kickstart file.
RHEL 7 from a kickstart file
Create a kickstart file that includes the following content and save the file. For information about kickstart installation, see the Kickstart Installation Guide.
# Kickstart for provisioning a RHEL 7 Azure VM # System authorization information auth --enableshadow --passalgo=sha512 # Use graphical install text # Don't run the Setup Agent on first boot firstboot --disable # Keyboard layouts keyboard --vckeymap=us --xlayouts='us' # System language lang en_US.UTF-8 # Network information network --bootproto=dhcp # Root password rootpw --plaintext "to_be_disabled" # System services services --enabled="sshd,waagent,NetworkManager" # System timezone timezone Etc/UTC --isUtc --ntpservers 0.rhel.pool.ntp.org,1.rhel.pool.ntp.org,2.rhel.pool.ntp.org,3.rhel.pool.ntp.org # Partition clearing information clearpart --all --initlabel # Clear the MBR zerombr # Disk partitioning information part /boot --fstype="xfs" --size=500 part / --fstyp="xfs" --size=1 --grow --asprimary # System bootloader configuration bootloader --location=mbr # Firewall configuration firewall --disabled # Enable SELinux selinux --enforcing # Don't configure X skipx # Power down the machine after install poweroff %packages @base @console-internet chrony sudo parted -dracut-config-rescue %end %post --log=/var/log/anaconda/post-install.log #!/bin/bash # Register Red Hat Subscription subscription-manager register --username=XXX --password=XXX --auto-attach --force # Install latest repo update yum update -y # Enable extras repo subscription-manager repos --enable=rhel-7-server-extras-rpms # Install WALinuxAgent yum install -y WALinuxAgent # Unregister Red Hat subscription subscription-manager unregister # Enable waaagent at boot-up systemctl enable waagent # Install cloud-init yum install -y cloud-init cloud-utils-growpart gdisk hyperv-daemons # Configure waagent for cloud-init sed -i 's/Provisioning.Agent=auto/Provisioning.Agent=cloud-init/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 echo "Adding mounts and disk_setup to init stage" sed -i '/ - mounts/d' /etc/cloud/cloud.cfg sed -i '/ - disk_setup/d' /etc/cloud/cloud.cfg sed -i '/cloud_init_modules/a\\ - mounts' /etc/cloud/cloud.cfg sed -i '/cloud_init_modules/a\\ - disk_setup' /etc/cloud/cloud.cfg # Disable the root account usermod root -p '!!' # Configure swap using cloud-init echo 'DefaultEnvironment="CLOUD_CFG=/etc/cloud/cloud.cfg.d/00-azure-swap.cfg"' >> /etc/systemd/system.conf cat > /etc/cloud/cloud.cfg.d/00-azure-swap.cfg << EOF #cloud-config # Generated by Azure cloud image build disk_setup: ephemeral0: table_type: mbr layout: [66, [33, 82]] overwrite: True fs_setup: - device: ephemeral0.1 filesystem: ext4 - device: ephemeral0.2 filesystem: swap mounts: - ["ephemeral0.1", "/mnt"] - ["ephemeral0.2", "none", "swap", "sw,nofail,x-systemd.device-timeout=2,x-systemd.requires=cloud-init.service", "0", "0"] EOF # Set the cmdline sed -i 's/^\(GRUB_CMDLINE_LINUX\)=".*"$/\1="console=tty1 console=ttyS0 earlyprintk=ttyS0"/g' /etc/default/grub # Enable SSH keepalive sed -i 's/^#\(ClientAliveInterval\).*$/\1 180/g' /etc/ssh/sshd_config # Build the grub cfg grub2-mkconfig -o /boot/grub2/grub.cfg # Configure network cat << EOF > /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE=eth0 ONBOOT=yes BOOTPROTO=dhcp TYPE=Ethernet USERCTL=no PEERDNS=yes IPV6INIT=no PERSISTENT_DHCLIENT=yes NM_CONTROLLED=yes EOF sudo cat <<EOF>> /etc/udev/rules.d/68-azure-sriov-nm-unmanaged.rules # Accelerated Networking on Azure exposes a new SRIOV interface to the VM. # This interface is transparentlybonded to the synthetic interface, # so NetworkManager should just ignore any SRIOV interfaces. SUBSYSTEM=="net", DRIVERS=="hv_pci", ACTION!="remove", ENV{NM_UNMANAGED}="1" EOF # Deprovision and prepare for Azure if you are creating a generalized image sudo cloud-init clean --logs --seed sudo rm -rf /var/lib/cloud/ sudo rm -rf /var/lib/waagent/ sudo rm -f /var/log/waagent.log sudo waagent -force -deprovision+user rm -f ~/.bash_history export HISTSIZE=0 %end
Place the kickstart file where the installation system can access it.
In Hyper-V Manager, create a new VM. On the Connect Virtual Hard Disk page, select Attach a virtual hard disk later, and complete the New Virtual Machine wizard.
Open the VM settings:
Attach a new VHD to the VM. Make sure to select VHD Format and Fixed Size.
Attach the installation ISO to the DVD drive.
Set the BIOS to boot from CD.
Start the VM. When the installation guide appears, select the Tab key to configure the boot options.
Enter
inst.ks=<the location of the kickstart file>
at the end of the boot options, and select the Enter key.Wait for the installation to finish. When it's finished, the VM shuts down automatically. Your Linux VHD is now ready to be uploaded to Azure.
Known issues
The following issue is known.
The Hyper-V driver couldn't be included in the initial RAM disk when using a non-Hyper-V hypervisor
In some cases, Linux installers might not include the drivers for Hyper-V in the initial RAM disk (initrd or initramfs) unless Linux detects that it's running in a Hyper-V environment.
When you're using a different virtualization system (for example, VirtualBox or Xen) to prepare your Linux image, you might need to rebuild initrd to ensure that at least the hv_vmbus
and hv_storvsc
kernel modules are available on the initial RAM disk. This issue is known, at least on systems that are based on the upstream Red Hat distribution.
To resolve this issue, add Hyper-V modules to initramfs and rebuild it:
Edit /etc/dracut.conf
, and add the following content:
add_drivers+=" hv_vmbus hv_netvsc hv_storvsc "
Rebuild initramfs:
sudo dracut -f -v
For more information, see Rebuilding initramfs.
Related content
- You're now ready to use your RHEL VHD to create new VMs 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.
- For more information about the hypervisors that are certified to run RHEL, see the Red Hat website.
- To learn more about using production-ready RHEL BYOS images, go to the documentation page for Bring your own subscription.