# VM creation

## Create a new VM

A new VM can be created via the "New" button in the main menu (bottom):

![](./assets/xo5vmcreatemenu.png)

Or in the home view:

![](./assets/xo5newvmbutton.png)

## Wizard

### Select your Pool

Because Xen Orchestra can be connected to multiple pools, you must select which one you want to create your VMs on:

![](./assets/xo5createonpool.png)

On which **host** the VM will actually run on will depend of various settings (local SR or not, RAM available etc.)

### Infos category

#### Select your template

The next step is to select a template:

![](./assets/xo5createwithtemplate.png)

> What is a XenServer template? It can be 2 things: first an "empty" template, meaning it contains only the configuration for your future VM, such as example settings (minimum disk size, RAM and CPU, BIOS settings if HVM etc.) Or it could be a previous VM you converted into a template: in this case, creating a VM will clone the existing disks.

#### Name and description

These values can be changed anytime after your VM is created.

#### Multiple VMs

You can create multiple VMs at once by toggling the _Multiple VMs_ option. The `{name}` pattern is the "Name" field of the VM. By default, it will start with number 1 and increment up. You can change this via the "First index" field.

Click on the refresh icon to see the change:

![](./assets/xo5multiplevms.png)

### Performance

This is where you can configure VM performance options: number of vCPUs, RAM, CPU weight and cap.

#### CPU weight and cap

The default CPU weight is `256` which means it will be scheduled by Xen like any other VMs on the host it runs from. If you raise it, eg with `512`, CPUs on this VM will be scheduled with twice the priority as others. If you decrease it, with `64` for example, it will be scheduled with 4 times less priority.

What about cap? It's the maximum amount of CPUs a VM can consume, using a 100 base (1 vCPU: 100). Default is 0 and means no upper cap.

> Should I mess with these settings? In general: nope. Change this only if you are sure of what are you doing. More can be found here: https://wiki.xen.org/wiki/Credit_Scheduler

### Install settings

Depending of your template type (with existing disks or not, PV vs HVM) this panel can be changed.

#### HVM templates without existing disks

You can choose to boot from an ISO or using PXE:

![](./assets/xo5installsettings.png)

#### PV templates

These templates will use PV configuration in order to boot: either from the right ISO or network URL. PV Args can be used to modify kernel parameters, but it's a very advanced setting you shouldn't play with.

#### Template with existing disks

Because there is already disks installed, you shouldn't have "Install settings" _per se_. But you can use our `config drive` setup if your template already has CloudInit installed!

Please refer to the [XenServer CloudInit section](cloudinit.md) for more.

### Interfaces

This is the network section of the VM configuration: in general, MAC field is kept empty (autogenerated from XenServer). We also select the management network by default, but you can change it to reflect your own network configuration.

### Disks

This section is for configuring new or existing disks (according to your selected template).

> Protip: avoid using large disks for your VMs. Want to store a lot of files? Use a network share for that (NFS, SMB) and keep using VMs with small system disks. It's far easier to maintain, migrate, backup and restore!