2.5. Cloning Virtual Machines and Containers

You can create a copy (clone) of a particular virtual machine or container that will have identical data and resource parameters. Cloning may save time as clones require little reconfiguration compared to setting up new virtual machines or containers.

You can clone stopped virtual machines and stopped and running containers. For example:

# prlctl clone MyCT --name MyCT_clone
# prlctl clone MyVM --name MyVM_clone

The --name option specifies a name for the clone.

When cloning Windows virtual machines, consider changing their security identifiers (SIDs) with the --changesid option.

Successfully cloned virtual machines and containers will be shown in the list of virtual environments on the host. For example:

# prlctl list -a
UUID            STATUS       IP_ADDR          T  NAME
{62951c2a-...}  stopped      10.30.10.101     CT MyCT
{49b66605-...}  stopped      10.30.10.101     CT MyCT_clone
{7f4904ad-...}  stopped      10.30.128.115    VM MyVM
{2afb2aa2-...}  stopped      10.30.128.134    VM MyVM_clone

The example above shows that the cloned container has the same IP address as the original container. Before starting to use the clones, make sure their IP addresses are unique (for instructions on how to assign IP addresses to VMs and containers, see Configuring Network Settings).

2.5.1. Creating Linked Clones

Starting from Virtuozzo 7.0.7 (Update 7), you can create linked clones of virtual machines. A linked clone is a copy of a virtual machine that shares virtual disks with the original virtual machine. Linked clones take less time and disk space to deploy as they store only changes to the original disks rather than copy them whole. A linked clone cannot run without access to its parent, so make sure the original virtual machine is available and its disks are not corrupted.

To create a linked clone, add the --linked option to the prlctl clone command. For example:

# prlctl clone MyVM --name MyVM_linked_clone --linked

On the host, linked clones are shown as usual virtual machines. For example:

# prlctl list -a
UUID            STATUS       IP_ADDR          T  NAME
{7f4904ad-...}  stopped      10.30.128.115    VM MyVM
{2e9862f6-...}  stopped      10.30.128.135    VM MyVM_linked_clone

Note

Migration, backup, restore, and unlink operations are not supported for linked clones.

2.5.2. Configuring Default Directories

When cloning a virtual machine or container, you can also override the following default directories:

  • default directory /vz/vmprivate/<dest_UUID> storing the files of a cloned virtual machine (where <dest_UUID> denotes the UUID of the resulting virtual machine). To store the files of the MyVM_clone virtual machine in a custom directory, you can run the following command:

    # prlctl clone MyVM --name MyVM_clone --dst vz/vmprivate/customVMs
    

    In this case all virtual machine files will be placed to the /customVMs directory. Note that the specified directory must exist on the server; otherwise, the command will fail.

  • default directory /vz/private/<dest_UUID> defining the container private area (where <dest_UUID> denotes the UUID of the resulting container). To define a custom private area path for the container MyCT_clone, you can execute the following command:

    # prlctl clone MyCT1 --name MyCT_clone --dst /vz/private/customCTs
    

Note

The default /vz/vmprivate and /vz/private are valid for servers that do not participate in Virtuozzo storage clusters.