1. KVM User's Guide
  2. Installation: Oracle Linux KVM
  3. Switch KVM Stacks

Switch KVM Stacks

You can switch from one KVM stack to another KVM stack, if required.

The KVM stacks define the versions of user space packages that you can use to manage virtual machines on Oracle Linux. To take advantage of newer functionality available in more recent user space packages, you must install UEK.

The Default KVM Stack is compatible with both RHCK and UEK. The Default KVM Stack is available from the standard Oracle Linux package repositories or ULN channels. If you require RHCK, you can only use the Default KVM Stack.

The Oracle KVM Stack, which includes more KVM features than the default stack, requires UEK to be running on the host system and that the system is subscribed to the appropriate yum repositories or ULN channels.

Switching the KVM stack on an Oracle Linux system involves removing one version of the KVM stack and then replacing it with another version of the KVM stack.

Caution:

Guests instances that were created by using one KVM stack might not be compatible and might not start after switching to another KVM stack.
For more details on how UEK users can switch between the KVM stacks, see these topics:

Note:

For details about the KVM stacks included in virtualization packages from a yum repository or ULN channel, see KVM Repositories and Channels: Yum and ULN.

Oracle Linux 9: Switch KVM Stacks

For instructions on how to switch KVM stacks on Oracle Linux 9 systems with UEK, see these topics:

Switch Default Stack to Oracle KVM Stack

The following information describes how Oracle Linux 9 users can switch from the Default KVM Stack to the Oracle KVM Stack.

Caution:

Guests instances that were created by using the default KVM stack might not be compatible and might not start after switching to the Oracle KVM stack.

What Do You Need?

  • Oracle Linux 9 system with the Default KVM Stack packages installed.
  • The host system must be running the latest UEK R7.
  • Administrator privileges.

Follow these steps to switch from the Default KVM stack to the Oracle KVM Stack.

  1. Remove any packages from the existing Default KVM Stack, for example: 
    sudo dnf remove libvirt* qemu* virt-install
  2. Enable the ol9_kvm_utils yum repository or ol9_<arch>_kvm_utils ULN channel.
  3. Install the required virtualization packages from the ol9_virt_utils yum repository or ol9_<arch>_virt_utils ULN channel: 
    sudo dnf install libvirt qemu-kvm virt-install

Switch Oracle KVM Stack to Default Stack

The following information describes how Oracle Linux 9 users can switch from the Oracle KVM stack to the Default KVM Stack.

Caution:

Guest instances that were created by using the Oracle KVM Stack might not be compatible and might not start after switching to the Default KVM Stack.

What Do You Need?

  • Oracle Linux 9 system with the Oracle KVM stack packages installed.
  • Administrator privileges.

Steps

Follow these steps to switch from the Oracle KVM Stack to the default KVM Stack.

  1. Remove any packages from the existing Oracle KVM Stack, for example: 
    sudo dnf remove libvirt* qemu* virt-install
  2. Disable the ol9_virt_utils yum repository or ol9_<arch>_virt_utils ULN channel.
  3. Install the required virtualization packages from the ol9_appstream yum repository or ol9_<arch>_appstream ULN channel. For example:
    sudo dnf install libvirt qemu-kvm virt-install

Oracle Linux 8: Switch KVM Stacks

For instructions on how to switch KVM stacks on Oracle Linux 8 systems with UEK, see these topics:

Switch Default Stack to Oracle KVM Stack

The following information describes how Oracle Linux 8 users can switch from the Default KVM Stack to the Oracle KVM Stack.

Caution:

Guests instances that were created by using the Default KVM Stack might not be compatible and might not start after switching to the Oracle KVM Stack.

What Do You Need?

  • Oracle Linux 8 system with the Default KVM Stack module installed.
  • The host system must be running the latest UEK R6 or UEK R7.
  • Administrator privileges.

Steps

Follow these steps to switch the KVM stack from the Default KVM Stack to the Oracle KVM Stack.

  1. Remove any packages from the existing default virt module stream: 
    sudo dnf module remove virt -y --all

    Note:

    Oracle Linux 8 virtualization stacks are managed by switching between application streams for the virt module. For more information about using DNF modules and application streams, see Oracle Linux: Managing Software on Oracle Linux
  2. Reset the virt module state so that it's neither enabled nor disabled: 
    sudo dnf module reset virt -y
  3. Enable the ol8_kvm_appstream yum repository or ol8_<arch>_kvm_appstream ULN channel.
  4. Enable the appropriate module and stream. For example, to use the latest packages: 
    sudo dnf module enable virt:kvm_utils3 -y
  5. Perform any necessary package upgrade or downgrade operations to handle dependencies for the enabled module and stream:
    sudo dnf --allowerasing distro-sync
  6. Install the base packages from the appropriate module and stream. For example, to use the latest packages: 
    sudo dnf module install virt:kvm_utils3 -y

Switch Oracle KVM Stack to Default Stack

The following information describes how Oracle Linux 8 users can switch from the Oracle KVM Stack to the Default KVM Stack.

Caution:

Guest instances that were created by using the Oracle KVM Stack might not be compatible and might not start after switching to the Default KVM Stack.

What Do You Need?

  • Oracle Linux 8 system with the Oracle KVM stack module and stream installed.
  • The host system must be running the latest UEK R6 or UEK R7. Administrator privileges.

Steps

Follow these steps to switch from the Oracle KVM Stack to the Default KVM Stack.

  1. Remove any of the packages from the existing Oracle KVM Stack module stream, for example: 
    sudo dnf module remove virt:kvm_utils3 -y --all

    Note:

    Oracle Linux 8 virtualization stacks are managed by switching between application streams for the virt module. For more information about using DNF modules and application streams, see Oracle Linux: Managing Software on Oracle Linux.
  2. Reset the virt module state so that it's neither enabled nor disabled: 
    sudo dnf module reset virt -y
  3. Enable the virt module and stream: 
    sudo dnf module enable virt -y
  4. Perform any necessary package upgrade or downgrade operations to handle dependencies for the enabled module and stream:
    sudo dnf --allowerasing distro-sync
  5. Install the base packages from the virt stream: 
    sudo dnf module install virt -y
  6. (Optional) Disable the ol8_kvm_appstream yum repository or ol8_<arch>_kvm_appstream ULN channel.
    You don't need to disable the ol8_kvm_appstream yum repository or ol8_<arch>_kvm_appstream ULN channel during this procedure, because DNF controls which application stream is installed, but if you don't intend to use the Oracle KVM stack it's good practice to disable the associated repository or channel to prevent confusion or possible conflicts in future.

Upgrade the Oracle KVM Stack

The following information describes how Oracle Linux 8 users can upgrade Oracle KVM Stack packages to the latest version of the Oracle KVM Stack by switching module streams.

Caution:

Guest instances that were created by using an earlier Oracle KVM Stack stream might not be compatible and might not start after switching to the later version of the Oracle KVM Stack.

What Do You Need?

  • Oracle Linux 8 system with the an earlier Oracle KVM Stack stream installed.
  • The host system must be running the latest UEK R6 or UEK R7.
  • Administrator privileges.

Steps

Follow these steps to switch from an earlier Oracle KVM Stack stream to the latest version of the Oracle KVM Stack.

  1. Remove any of the packages from the existing Oracle KVM Stack. For example, to switch from the virt:kvm_utils2 module stream:
    sudo dnf module remove virt:kvm_utils2 -y --all

    Note:

    Oracle Linux 8 virtualization stacks are managed by switching between application streams for the virt module. For more information about using DNF modules and application streams, see Oracle Linux: Managing Software on Oracle Linux.
  2. Reset the virt module state so that it's neither enabled nor disabled: 
    sudo dnf module reset virt -y
  3. Enable the latest module and stream. For example, to enable virt:kvm_utils3: 
    sudo dnf module enable virt:kvm_utils3 -y
  4. Perform any necessary package upgrade or downgrade operations to handle dependencies required for the enabled module and stream:
    sudo dnf --allowerasing distro-sync
  5. Install the later version of the Oracle KVM Stack packages. For example, to install the packages from virt:kvm_utils3:
    sudo dnf module install virt:kvm_utils3 -y

Oracle Linux 7: Switch KVM Stacks

WARNING:

Oracle Linux 7 is now in Extended Support. See Oracle Linux Extended Support and Oracle Open Source Support Policies for more information.

Migrate applications and data to Oracle Linux 8 or Oracle Linux 9 as soon as possible.

For instructions on how to switch KVM stacks on Oracle Linux 7 systems with UEK, see these topics:

Switch Default Stack to Oracle KVM Stack

The following information describes how Oracle Linux 7 UEK users can switch from the Default KVM Stack to the Oracle KVM Stack.

Caution:

Guest instances that were created by using the Default KVM Stack might not be compatible and might not start after switching to the Oracle KVM Stack.

What Do You Need?

  • Oracle Linux 7 UEK system with the Default KVM Stack packages installed.
  • Administrator privileges.

Steps

Follow these steps to switch from the Default KVM Stack to the Oracle KVM Stack.

  1. Remove any packages from the existing Default KVM Stack, for example: 
    sudo yum remove libvirt* qemu* virt-install
  2. Enable the ol7_kvm_utils yum repository or ol7_<arch>_kvm_utils ULN channel.
  3. Install the required virtualization packages from the ol7_virt_utils yum repository or ol7_<arch>_virt_utils ULN channel: 
    sudo yum install libvirt qemu-kvm virt-install

Switch Oracle KVM Stack to Default Stack

The following information describes how Oracle Linux 7 UEK users can switch from the Oracle KVM Stack to the Default KVM stack.

Caution:

Guests instances that were created by using the Oracle KVM Stack might not be compatible and might not start after switching to the Default KVM stack.

What Do You Need?

  • Oracle Linux 7 UEK system with the Oracle KVM stack installed.
  • Administrator privileges.

Steps

Follow these steps to switch from the Oracle KVM Stack to the Default KVM Stack.

  1. Remove any packages from the existing Oracle KVM Stack, for example: 
    sudo yum remove libvirt* qemu* virt-install
  2. Disable the ol7_virt_utils yum repository or ol7_<arch>_virt_utils ULN channel.
  3. Install the required virtualization packages from the ol7_latest yum repository or ol7_<arch>_latest ULN channel. For example:
    sudo yum --disablerepo="*" --enablerepo="ol7_latest" install libvirt qemu-kvm virt-install