Android Virtual Devices

AVD quickview

  • You need to create an AVD to run any app in the Android emulator
  • Each AVD is a completely independent virtual device, with its own hardware options, system image, and data storage.
  • You create AVD configurations to model different device environments in the Android emulator.
  • You can launch a graphical Android AVD Manager either through Eclipse or through the android tool. The android tool also offers a command-line interface for creating and managing AVDs.

In this document

  1. Creating an AVD
    1. Setting hardware emulation options
    2. Default location of the AVD files
  2. Managing AVDs
    1. Moving an AVD
    2. Updating an AVD
    3. Deleting an AVD
  3. Command-line options

See Also

  1. Android Emulator

Android Virtual Devices (AVDs) are configurations of emulator options that let you better model an actual device.

Each AVD is made up of:

  • A hardware profile.  You can set options to define the hardware features of the virtual device. For example, you can define whether the device has a camera, whether it uses a physical QWERTY keyboard or a dialing pad, how much memory it has, and so on.
  • A mapping to a system image.  You can define what version of the Android platform will run on the virtual device. You can choose a version of the standard Android platform or the system image packaged with an SDK add-on.
  • Other options.  You can specify the emulator skin you want to use with the AVD, which lets you control the screen dimensions, appearance, and so on. You can also specify the emulated SD card to use with the AVD.
  • A dedicated storage area on your development machine, in which is stored the device's user data (installed applications, settings, and so on) and emulated SD card.

You can create as many AVDs as you need, based on the types of devices you want to model and the Android platforms and external libraries you want to run your application on.

In addition to the options in an AVD configuration, you can also specify emulator command-line options at launch or by using the emulator console to change behaviors or characteristics at run time. For a complete reference of emulator options, please see the Emulator documentation.

The easiest way to create an AVD is to use the graphical AVD Manager, which you can launch from Eclipse or from the command line using the android tool. The android tool is provided in the tools/ directory of the Android SDK. When you run the android tool without options, it launches the graphical AVD Manager.

For more information about how to work with AVDs from inside your development environment, see Developing in Eclipse with ADT or Developing in Other IDEs, as appropriate for your environment.

Creating an AVD

The Android SDK does not include any preconfigured AVDs, so you need to create an AVD before you can run any application in the emulator (even the Hello World application).

The easiest way to create an AVD is to use the graphical AVD Manager, but the android tool also offers a command line option.

To create an AVD:

  1. In Eclipse, choose Window > Android SDK and AVD Manager.

    2. Alternatively, you can launch the graphical AVD Manager by running the android tool with no options.

  2. Select Virtual Devices in the left panel.
  3. Click New.

    4. The Create New AVD dialog appears.

    AVD Dialog
  4. Type the name of the AVD, such as "my_avd".
  5. Choose a target.

    6. The target is the system image that you want to run on the emulator, from the set of platforms that are installed in your SDK environment. You can choose a version of the standard Android platform or an SDK add-on. For more information about how to add platforms to your SDK, see Adding SDK Components.

  6. Optionally specify any additional settings:
    7. SD Card
    The path to the SD card image to use with this AVD, or the size of a new SD card image to create for this AVD.
    Skin
    The skin to use for this AVD, identified by name or dimensions.
    Hardware
    The hardware emulation options for the device. For a list of the options, see Setting hardware emulation options.
  7. Click Create AVD.

Setting hardware emulation options

When you create a new AVD that uses a standard Android system image ("Type: platform"), the AVD Manager lets you set hardware emulation options for your virtual device. The table below lists the options available and the default values, as well as the names of properties that store the emulated hardware options in the AVD's configuration file (the config.ini file in the AVD's local directory).

Characteristic Description Property
Device ram size The amount of physical RAM on the device, in megabytes. Default value is "96". hw.ramSize
Touch-screen support Whether there is a touch screen or not on the device. Default value is "yes". hw.touchScreen
Trackball support Whether there is a trackball on the device. Default value is "yes". hw.trackBall
Keyboard support Whether the device has a QWERTY keyboard. Default value is "yes". hw.keyboard
DPad support Whether the device has DPad keys. Default value is "yes". hw.dPad
GSM modem support Whether there is a GSM modem in the device. Default value is "yes". hw.gsmModem
Camera support Whether the device has a camera. Default value is "no". hw.camera
Maximum horizontal camera pixels Default value is "640". hw.camera.maxHorizontalPixels
Maximum vertical camera pixels Default value is "480". hw.camera.maxVerticalPixels
GPS support Whether there is a GPS in the device. Default value is "yes". hw.gps
Battery support Whether the device can run on a battery. Default value is "yes". hw.battery
Accelerometer Whether there is an accelerometer in the device. Default value is "yes". hw.accelerometer
Audio recording support Whether the device can record audio. Default value is "yes". hw.audioInput
Audio playback support Whether the device can play audio. Default value is "yes". hw.audioOutput
SD Card support Whether the device supports insertion/removal of virtual SD Cards. Default value is "yes". hw.sdCard
Cache partition support Whether we use a /cache partition on the device. Default value is "yes". disk.cachePartition
Cache partition size Default value is "66MB". disk.cachePartition.size
Abstracted LCD density Sets the generalized density characteristic used by the AVD's screen. Most skins come with a value (which you can modify), but if a skin doesn't provide its own value, the default is 160. hw.lcd.density
Max VM application heap size The maximum heap size a Dalvik application might allocate before being killed by the system. Value is in megabytes. Most skins come with a value (which you can modify), but if a skin doesn't provide its own value, the default is 16. vm.heapSize

Default location of the AVD files

When you create an AVD, the AVD Manager creates a dedicated directory for it on your development computer. The directory contains the AVD configuration file, the user data image and SD card image (if available), and any other files associated with the device. Note that the directory does not contain a system image — instead, the AVD configuration file contains a mapping to the system image, which it loads when the AVD is launched.

The AVD Manager also creates a <AVD name>.ini file for the AVD at the root of the .android/avd directory on your computer. The file specifies the location of the AVD directory and always remains at the root the .android directory.

By default, the AVD Manager creates the AVD directory inside ~/.android/avd/ (on Linux/Mac), C:\Documents and Settings\<user>\.android\ on Windows XP, and C:\Users\<user>\.android\ on Windows Vista. If you want to use a custom location for the AVD directory, you can do so by using the -p <path> option when you create the AVD (command line tool only): 

android create avd -n my_android1.5 -t 2 -p path/to/my/avd

If the .android directory is hosted on a network drive, we recommend using the -p option to place the AVD directory in another location. The AVD's .ini file remains in the .android directory on the network drive, regardless of the location of the AVD directory.

Managing AVDs

The sections below provide more information about how to manage AVDs once you've created them.

Moving an AVD

If you want to move or rename an AVD, you can do so using this command:

android move avd -n <name> [-<option> <value>] ...

The options for this command are listed in Command-line options for AVDs at the bottom of this page.

Updating an AVD

If you rename or move the root directory of a platform (or add-on), an AVD configured to use that platform will no longer be able to load the system image properly. To fix the AVD, use the Repair... button in the AVD Manager. From the command line, you can also use the android update avd command to recompute the path to the system images.

Deleting an AVD

You can delete an AVD in the AVD Manager by selecting the AVD and clicking Delete.

Alternatively, you can use the android tool to delete an AVD. Here is the command usage:

android delete avd -n <name>

When you issue the command, the android tool looks for an AVD matching the specified name deletes the AVD's directory and files.

Command-line options

You can use the android tool to create and manage AVDs.

The command line for creating an AVD has the following syntax:

android create avd -n <name> -t <targetID> [-<option> <value>] ...

Here's an example that creates an AVD with the name "my_android2.2" and target ID "3":

android create avd -n my_android2.2 -t 3

The table below lists the command-line options you can use with the android tool.

Action Option Description Comments
list avds   List all known AVDs, with name, path, target, and skin.  
create avd -n <name> or
The name for the AVD. Required
-t <targetID> Target ID of the system image to use with the new AVD. Required. To obtain a list of available targets, use android list targets.
-c <path> or
-c <size>[K|M]		 The path to the SD card image to use with this AVD or the size of a new SD card image to create for this AVD. Examples: -c path/to/sdcard or -c 1000M
-f Force creation of the AVD By default, if the name of the AVD being created matches that of an existing AVD, the android tool will not create the new AVD or overwrite the existing AVD. If you specify the -f option, however, the android tool will automatically overwrite any existing AVD that has the same name as the new AVD. The files and data of the existing AVD are deleted.
-p <path> Path to the location at which to create the directory for this AVD's files.  
-s <name> or
-s <width>-<height> 		The skin to use for this AVD, identified by name or dimensions. The android tool scans for a matching skin by name or dimension in the skins/ directory of the target referenced in the -t <targetID> argument. Example: -s HVGA-L
delete avd -n <name> Delete the specified AVD. Required
move avd -n <name> The name of the AVD to move. Required
-p <path> The path to the new location for the AVD.  
-r <new-name> Rename the AVD.  
update avds   Recompute the paths to all system images.  
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