How to use the command 'qm create' (with examples)

The qm create command is a versatile utility used for creating or restoring virtual machines in the QEMU/KVM Virtual Machine Manager environment. Primarily associated with the Proxmox Virtual Environment, it facilitates flexible machine deployments and configurations. Its powerful argument options enable users to tailor virtual machines to meet specific computing needs or to recover setups from backups. Whether it’s initializing fresh installations, automating operations, or managing archival systems, qm create is essential for managing virtual infrastructures efficiently.

Use case 1: Create a virtual machine

Code:

qm create 100

Motivation:

Creating a virtual machine is the foundational step in building a virtualized environment. By executing the simple command qm create 100, an administrator can quickly set up a new virtual machine with a unique identifier which serves as a placeholder for subsequent configurations.

Explanation:

• qm create: Invokes the command line tool responsible for creating a new virtual machine.
• 100: The unique VM ID for the new virtual machine. This serves as the primary identifier within the Proxmox environment.

Example Output:

Upon execution, the system may not provide explicit output in the terminal, but the virtual machine ID 100 is allocated and can now be subject to further configurations via additional management commands or through a graphical user interface in the Proxmox VE.

Use case 2: Automatically start the machine after creation

Code:

qm create 100 --start 1

Motivation:

There are scenarios where an administrator needs a virtual machine to be operational immediately after creation. This is particularly useful in testing environments or when deploying applications that require immediate availability. Ensuring that a machine boots up as soon as it is created reduces manual intervention and aligns with automated deployment practices.

Explanation:

• qm create: Command used to initialize a new VM.
• 100: The assigned VM ID for this machine.
• --start 1: An option that signals the system to automatically boot the virtual machine upon creation. The value 1 conventionally indicates a boolean ’true’ for this parameter.

Example Output:

The command completed its process, and you would observe that the VM ID 100 transitions to a running state if queried or listed using Proxmox’s management tools.

Use case 3: Specify the type of operating system on the machine

Code:

qm create 100 --ostype win10

Motivation:

When deploying virtual machines, it is crucial to correctly specify the type of operating system intended for installation. This setting helps optimize the machine’s configuration for the OS’s specific requirements and can enable features such as improved graphics, optimized performance, and certain OS-specific capabilities.

Explanation:

• qm create: The command to initiate a new VM.
• 100: The unique identifier for this virtual machine instance.
• --ostype win10: This option specifies that the virtual machine will host a Windows 10 operating system. The --ostype flag is crucial for tailoring virtual hardware compatibility and ensuring resource allocation matches the OS’s demands.

Example Output:

The completion of this command associates the VM ID 100 with the configuration settings optimal for a Windows 10 environment, which can be verified through various configuration management tools provided by Proxmox.

Use case 4: Replace an existing machine (requires archiving it)

Code:

qm create 100 --archive path/to/backup_file.tar --force 1

Motivation:

There are instances where an older machine setup needs to be replaced or restored due to hardware failure, data corruption, or updating requirements. Using an archival backup allows the administrator to re-establish the machine in its entirety without manual reconfiguration. The --force option ensures that existing structures are overwritten as needed.

Explanation:

• qm create: Command to create or restore a VM.
• 100: The VM ID targeted for restoration or replacement.
• --archive path/to/backup_file.tar: Directs the system to use a specific archive file located at path/to/backup_file.tar to restore the VM’s state.
• --force 1: An option applied to overwrite existing virtual machine settings or files with those in the backup, with 1 serving as an equivalent to a boolean ’true'.

Example Output:

This command results in the VM ID 100 being restored or replaced with the configuration and data from the specified backup archive. The process may conclude with confirmation logs detailing the restoration success.

Use case 5: Specify a script that is executed automatically depending on the state of the virtual machine

Code:

qm create 100 --hookscript path/to/script.pl

Motivation:

In complex or automated setups, administrators might need specific scripts to execute during certain states or events, such as startup, shutdown, or failover situations. Specifying a hookscript helps in automating tasks, managing resources, or performing maintenance actions without manual interaction.

Explanation:

• qm create: The initial command for creating a VM.
• 100: The VM ID intended for scripting execution.
• --hookscript path/to/script.pl: Sets a script located at the specified path to run automatically on a predefined state change of the virtual machine. This will enable lifecycle customizations tied to the script contents.

Example Output:

Following successful execution, the Proxmox framework incorporates the specified script script.pl as part of the VM’s state management process. Depending on the script’s design, it will execute at corresponding life cycle events throughout its operation.

Conclusion:

The qm create command is paramount for virtual machine setup and management within the Proxmox environment. Its capability to customize and automate operations through various options like --start, --ostype, --archive, and --hookscript makes it an indispensable tool for administrators seeking efficiency and reliability in managing virtual infrastructures. These detailed examples elucidate the opportunities for leveraging qm create in creating tailored and efficient VM deployments.