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<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 class="devsite-click-to-copy">
[physical device node]  auto  vfat  defaults  voldmanaged=sdcard0:auto,noemulatedsd
</pre>
<h4>init.hardware.rc</h4>
<pre class="devsite-click-to-copy">
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
</pre>
<h4>storage_list.xml</h4>
<pre class="devsite-click-to-copy">
&lt;storage
    android:mountPoint="/storage/sdcard0"
    android:storageDescription="@string/storage_sd_card"
    android:removable="true"
    android:primary="true"
    android:maxFileSize="4096" /&gt;
</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 class="devsite-click-to-copy">
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
</pre>
<h4>storage_list.xml</h4>
<pre class="devsite-click-to-copy">
&lt;storage
    android:storageDescription="@string/storage_internal"
    android:emulated="true"
    android:mtpReserve="100" /&gt;
</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 class="devsite-click-to-copy">
[physical device node]  auto  vfat  defaults  voldmanaged=sdcard1:auto
</pre>
<h4>init.hardware.rc</h4>
<pre class="devsite-click-to-copy">
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
</pre>
<h4>storage_list.xml</h4>
<pre class="devsite-click-to-copy">
&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;
</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 class="devsite-click-to-copy">
/devices/platform/mtk-msdc.1/mmc_host*         auto        auto       defaults
voldmanaged=sdcard0:auto,encryptable=userdata,noemulatedsd
</pre>
<h4>init.device.rc</h4>
<pre class="devsite-click-to-copy">
on init
    # By default, primary storage is physical
    setprop ro.vold.primary_physical 1
</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 class="devsite-click-to-copy">/devices/*/xhci-hcd.0.auto/usb*             auto            auto    defaults
                                                    voldmanaged=usb:auto
</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 class="devsite-click-to-copy">
/devices/platform/mtk-msdc.1/mmc_host*           auto      auto     defaults
voldmanaged=sdcard1:auto,encryptable=userdata
</pre>

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