packer-cn/website/source/docs/builders/qemu.html.md.erb

---
modeline: |
  vim: set ft=pandoc:
description: |
    The Qemu Packer builder is able to create KVM and Xen virtual machine images.
layout: docs
page_title: 'QEMU - Builders'
sidebar_current: 'docs-builders-qemu'
---

# QEMU Builder

Type: `qemu`

The Qemu Packer builder is able to create [KVM](http://www.linux-kvm.org) and
[Xen](http://www.xenproject.org) virtual machine images.

The builder builds a virtual machine by creating a new virtual machine from
scratch, booting it, installing an OS, rebooting the machine with the boot media
as the virtual hard drive, provisioning software within the OS, then shutting it
down. The result of the Qemu builder is a directory containing the image file
necessary to run the virtual machine on KVM or Xen.

## Basic Example

Here is a basic example. This example is functional so long as you fixup paths
to files, URLS for ISOs and checksums.

``` json
{
  "builders":
  [
    {
      "type": "qemu",
      "iso_url": "http://mirror.raystedman.net/centos/6/isos/x86_64/CentOS-6.9-x86_64-minimal.iso",
      "iso_checksum": "af4a1640c0c6f348c6c41f1ea9e192a2",
      "iso_checksum_type": "md5",
      "output_directory": "output_centos_tdhtest",
      "shutdown_command": "echo 'packer' | sudo -S shutdown -P now",
      "disk_size": 5000,
      "format": "qcow2",
      "accelerator": "kvm",
      "http_directory": "path/to/httpdir",
      "ssh_username": "root",
      "ssh_password": "s0m3password",
      "ssh_timeout": "20m",
      "vm_name": "tdhtest",
      "net_device": "virtio-net",
      "disk_interface": "virtio",
      "boot_wait": "10s",
      "boot_command": [
        "<tab> text ks=http://{{ .HTTPIP }}:{{ .HTTPPort }}/centos6-ks.cfg<enter><wait>"
      ]
    }
  ]
}
```

This is an example only, and will time out waiting for SSH because we have not
provided a kickstart file. You must add a valid kickstart file to the
"http_directory" and then provide the file in the "boot_command" in order for
this build to run. We recommend you check out the
[Community Templates](https://www.packer.io/community-tools.html#templates)
for a practical usage example.

## Configuration Reference

There are many configuration options available for the Qemu builder. They are
organized below into two categories: required and optional. Within each
category, the available options are alphabetized and described.

In addition to the options listed here, a
[communicator](/docs/templates/communicator.html) can be configured for this
builder.

Note that you will need to set `"headless": true` if you are running Packer
on a Linux server without X11; or if you are connected via ssh to a remote
Linux server and have not enabled X11 forwarding (`ssh -X`).


## ISO Configuration Reference

<%= partial "partials/common/ISOConfig" %>

### Required:

<%= partial "partials/common/ISOConfig-required" %>

### Optional:

<%= partial "partials/common/ISOConfig-not-required" %>

## Http directory configuration reference

<%= partial "partials/common/HTTPConfig" %>
### Optional:

<%= partial "partials/common/HTTPConfig-not-required" %>

## Qemu Configuration Reference

### Optional:
<%= partial "partials/builder/qemu/Config-not-required" %>
DADA

-   `boot_command` (array of strings) - This is an array of commands to type
    when the virtual machine is first booted. The goal of these commands should
    be to type just enough to initialize the operating system installer. Special
    keys can be typed as well, and are covered in the section below on the
    boot command. If this is not specified, it is assumed the installer will
    start itself.

-   `boot_wait` (string) - The time to wait after booting the initial virtual
    machine before typing the `boot_command`. The value of this should be
    a duration. Examples are `5s` and `1m30s` which will cause Packer to wait
    five seconds and one minute 30 seconds, respectively. If this isn't
    specified, the default is `10s` or 10 seconds.

-   `floppy_dirs` (array of strings) - A list of directories to place onto
    the floppy disk recursively. This is similar to the `floppy_files` option
    except that the directory structure is preserved. This is useful for when
    your floppy disk includes drivers or if you just want to organize it's
    contents as a hierarchy. Wildcard characters (\*, ?, and \[\]) are allowed.
    The maximum summary size of all files in the listed directories are the
    same as in `floppy_files`.

-   `floppy_files` (array of strings) - A list of files to place onto a floppy
    disk that is attached when the VM is booted. This is most useful for
    unattended Windows installs, which look for an `Autounattend.xml` file on
    removable media. By default, no floppy will be attached. All files listed in
    this setting get placed into the root directory of the floppy and the floppy
    is attached as the first floppy device. Currently, no support exists for
    creating sub-directories on the floppy. Wildcard characters (\*, ?,
    and \[\]) are allowed. Directory names are also allowed, which will add all
    the files found in the directory to the floppy. The summary size of the
    listed files must not exceed 1.44 MB. The supported ways to move large
    files into the OS are using `http_directory` or [the file provisioner](https://www.packer.io/docs/provisioners/file.html).


## Boot Command

The `boot_command` configuration is very important: it specifies the keys to
type when the virtual machine is first booted in order to start the OS
installer. This command is typed after `boot_wait`, which gives the virtual
machine some time to actually load the ISO.

As documented above, the `boot_command` is an array of strings. The strings are
all typed in sequence. It is an array only to improve readability within the
template.

The boot command is "typed" character for character over a VNC connection to the
machine, simulating a human actually typing the keyboard.

-&gt; Keystrokes are typed as separate key up/down events over VNC with a
default 100ms delay. The delay alleviates issues with latency and CPU
contention. You can tune this delay on a per-builder basis by specifying
"boot_key_interval" in your Packer template, for example:

```
{
  "builders": [
    {
      "type": "qemu",
      "boot_key_interval": "10ms"
      ...
    }
  ]
}
```

<%= partial "partials/builders/boot-command" %>

Example boot command. This is actually a working boot command used to start an
CentOS 6.4 installer:

``` json
{
"boot_command": [
    "<tab><wait>",
    " ks=http://{{ .HTTPIP }}:{{ .HTTPPort }}/centos6-ks.cfg<enter>"
  ]
}
```

For more examples of various boot commands, see the sample projects from our
[community templates page](/community-tools.html#templates).

### Troubleshooting

Some users have experienced errors complaining about invalid keymaps. This
seems to be related to having a `common` directory or file in the directory
they've run Packer in, like the packer source directory. This appears to be an
upstream bug with qemu, and the best solution for now is to remove the
file/directory or run in another directory.

Some users have reported issues with incorrect keymaps using qemu version 2.11.
This is a bug with qemu, and the solution is to upgrade, or downgrade to 2.10.1
or earlier.