en/devices/storage/config-example.html

page.title=Configuration Examples
@jd:body
<!--
    Copyright 2015 The Android Open Source Project
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at
        http://www.apache.org/licenses/LICENSE-2.0
    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
-->
<div id="qv-wrapper">
  <div id="qv">
    <h2>In this document</h2>
    <ol id="auto-toc">
    </ol>
  </div>
</div>

<p>Below are examples of external storage configurations
for various device types. Only the relevant portions of the configuration
files are included.
<p>Due to configuration changes in Android 6.0 (like the removal of the
<code>storage_list.xml</code> resource overlay), the configuration examples are
split into two categories.</p>

<h2 id=android_5_x>Android 5.x and earlier</h2>
<h3 id=android_5_x_physical>Physical primary only</h3>
<p>This is a typical configuration for a device with single external storage
device which is a physical SD card, like Nexus One.</p>
<p>The raw physical device must first be mounted under
<code>/mnt/media_rw</code> where only the system and FUSE daemon can access
it. <code>vold</code> will then manage the <code>fuse_sdcard0</code> service
when media is inserted/removed.
<h4>fstab.hardware</h4>
<pre><code>[physical device node]  auto  vfat  defaults  voldmanaged=sdcard0:auto,noemulatedsd
</code></pre>
<h4>init.hardware.rc</h4>
<pre><code>on init
    mkdir /mnt/media_rw/sdcard0 0700 media_rw media_rw
    mkdir /storage/sdcard0 0700 root root
    export EXTERNAL_STORAGE /storage/sdcard0
service fuse_sdcard0 /system/bin/sdcard -u 1023 -g 1023 -d /mnt/media_rw/sdcard0 /storage/sdcard0
    class late_start
    disabled
</code></pre>
<h4>storage_list.xml</h4>
<pre><code>&lt;storage
    android:mountPoint="/storage/sdcard0"
    android:storageDescription="@string/storage_sd_card"
    android:removable="true"
    android:primary="true"
    android:maxFileSize="4096" /&gt;
</code></pre>
<h3 id=android_5_x_emulated>Emulated primary only</h3>
<p>This is a typical configuration for a device with single external storage
device which is backed by internal storage on the device, like Nexus 4.</p>
<h4>init.hardware.rc</h4>
<pre><code>on init
    mkdir /mnt/shell/emulated 0700 shell shell
    mkdir /storage/emulated 0555 root root
    export EXTERNAL_STORAGE /storage/emulated/legacy
    export EMULATED_STORAGE_SOURCE /mnt/shell/emulated
    export EMULATED_STORAGE_TARGET /storage/emulated
on fs
    setprop ro.crypto.fuse_sdcard true
service sdcard /system/bin/sdcard -u 1023 -g 1023 -l /data/media /mnt/shell/emulated
    class late_start
</code></pre>
<h4>storage_list.xml</h4>
<pre><code>&lt;storage
    android:storageDescription="@string/storage_internal"
    android:emulated="true"
    android:mtpReserve="100" /&gt;
</code></pre>
<h3 id=android_5_x_both>Emulated primary, physical secondary</h3>
<p>This is a typical configuration for a device with multiple external
storage devices, where the primary device is backed by internal storage
on the device, and where the secondary device is a physical SD card, like Xoom.</p>
<p>The raw physical device must first be mounted under
<code>/mnt/media_rw</code> where only the system and FUSE daemon can
access it. <code>vold</code> will then manage the <code>fuse_sdcard1</code>
service when media is inserted/removed.</p>
<h4>fstab.hardware</h4>
<pre><code>[physical device node]  auto  vfat  defaults  voldmanaged=sdcard1:auto
</code></pre>
<h4>init.hardware.rc</h4>
<pre><code>on init
    mkdir /mnt/shell/emulated 0700 shell shell
    mkdir /storage/emulated 0555 root root
    mkdir /mnt/media_rw/sdcard1 0700 media_rw media_rw
    mkdir /storage/sdcard1 0700 root root
    export EXTERNAL_STORAGE /storage/emulated/legacy
    export EMULATED_STORAGE_SOURCE /mnt/shell/emulated
    export EMULATED_STORAGE_TARGET /storage/emulated
    export SECONDARY_STORAGE /storage/sdcard1
on fs
    setprop ro.crypto.fuse_sdcard true
service sdcard /system/bin/sdcard -u 1023 -g 1023 -l /data/media /mnt/shell/emulated
    class late_start
service fuse_sdcard1 /system/bin/sdcard -u 1023 -g 1023 -w 1023 -d /mnt/media_rw/sdcard1 /storage/sdcard1
    class late_start
    disabled
</code></pre>
<h4>storage_list.xml</h4>
<pre><code>&lt;storage
    android:storageDescription="@string/storage_internal"
    android:emulated="true"
    android:mtpReserve="100" /&gt;
&lt;storage
    android:mountPoint="/storage/sdcard1"
    android:storageDescription="@string/storage_sd_card"
    android:removable="true"
    android:maxFileSize="4096" /&gt;
</code></pre>

<h2 id=android_6>Android 6.0</h2>
<h3 id=android_6_physical>Physical primary only</h3>
<p>This is a typical configuration for a device with single external storage
device which is a physical SD card, like the original Android One. There is no
secondary shared storage and the device cannot support multi-user.</p>
<h4>fstab.device</h4>
<pre><code>/devices/platform/mtk-msdc.1/mmc_host*         auto        auto       defaults
voldmanaged=sdcard0:auto,encryptable=userdata,noemulatedsd
</code></pre>
<h4>init.device.rc</h4>
<pre><code>on init
    # By default, primary storage is physical
    setprop ro.vold.primary_physical 1
    </code></pre>
<h3 id=android_6_emulated> Emulated primary only</h3>
<p>This is a typical configuration for a device with single external storage
device which is backed by internal storage on the device, like Nexus 6.</p>
<ul>
  <li>Primary shared storage (<code>/sdcard</code>) is emulated on top of internal storage.
  <li>No secondary SD card storage.
  <li>USB OTG storage devices supported.
  <li>Supports multi-user.
</ul>
<h4>fstab.device</h4>
<pre><code>/devices/*/xhci-hcd.0.auto/usb*             auto            auto    defaults
                                                    voldmanaged=usb:auto</code></pre>
<h3 id=android_6_both>Emulated primary, physical secondary</h3>
<p>This is a typical configuration for a device with multiple external storage
devices, where the primary device is backed by internal storage on the device,
and where the secondary device is a physical SD card, like Xoom.</p>
<ul>
  <li>Primary shared storage (<code>/sdcard</code>) is emulated on top of internal storage.
  <li>Secondary storage is a physical SD card slot that can be adopted.
  <li>Supports multi-user.
</ul>
<h4>fstab.device</h4>
<pre><code>/devices/platform/mtk-msdc.1/mmc_host*           auto      auto     defaults
voldmanaged=sdcard1:auto,encryptable=userdata
</code></pre>