Skip to content

Android Storage

Jump to bottom
raisercostin edited this page Aug 5, 2017 · 9 revisions

Android changed the way you get storage permissions. Here is a summary of the changes:

Issues

On 5.0.1 some apps still use WRITE_EXTERNAL_STORAGE(gid sdcard_rw) and not WRITE_MEDIA_STORAGE(gid media_rw) permissions (stored in /etc/system/platform.xml). See here how to fix if you have a rooted phone.

Conclusions

samsung - young - 4.1

I have /storage.sdcard0 as space I have /storage/extSdCard for a removable sdcard.

Notions

Titanium Backup classifies them into:

  • System ROM - (100MB - 3GB)
  • Internal + Media (100MB - 9G)
  • Ext. SD card
  • Filesystem Storage (/) - For all ANdroid versions. Android 4.4+ may restrict access to some storage locations.
  • DocumentProvider Storage - Requires Android 5.0+ and a suitable DocumentProvider. Pick the location you want to give TB access to, and then create a subdirectory for your backups.
  • Filesystem Storage - Ext. SD card (/mnt/extSdCard) - For all Android versions. Android 4.4+ may restrict access to some storage locations.
  • Filesystem Storage - Media (/storage/emulated/legacy) - For all Android versions. Android 4.4+ may restrict access to some storage locations.

Internal/External - Removable/NonRemovable

  • Internal Storage - By default, files saved to the internal storage are private to your application and other applications cannot access them (nor can the user). Usually: /data/data/your.application.package.appname/someDirectory/. This could be accessed via AndroidStudio or if the devices is rooted.
  • NonRemovable External Storage - Eg: /storage/emulated/0
  • Removable External Storage - This can be a removable storage media (such as an SD card) or an internal (non-removable) storage. Eg: /storage/extSdCard

Primary/Secondary

  • Primary -
  • Secondary -

SingleUser/MultiUser

Before Android 4.2, only one user could user your phone. There was no concept of two or more users creating separate profiles and logging into the same phone.
As a result, there were no such paths like /storage/emulated/someDirectory The emulated directories came up after the introduction of multiuser API in Android 4.2.

Versions

Code name Version number Initial release date API level Support status[3] Storage Permissions
(No codename)[4] 1.0 September 23, 2008 1 Unsupported
(Internally known as "Petit Four")[4] 1.1 February 9, 2009 2 Unsupported
Cupcake 1.5 April 27, 2009 3 Unsupported
Donut[5] 1.6 September 15, 2009 4 Unsupported
Eclair[6] 2.0–2.1 October 26, 2009 5–7 Unsupported
Froyo[7] 2.2–2.2.3 May 20, 2010 8 Unsupported
Gingerbread[8] 2.3–2.3.7 December 6, 2010 9–10 Unsupported
Honeycomb[9] 3.0–3.2.6 February 22, 2011 11–13 Unsupported Disallowsapplications from having write access to secondary storage (memory cards on devices with internal primary storage) outside of designated, application-specific directories. Full access to primary internal storage is still allowed through a separate application-level permission.
Ice Cream Sandwich[10] 4.0–4.0.4 October 18, 2011 14–15 Unsupported
Jelly Bean[11] 4.1–4.3.1 July 9, 2012 16–18 Unsupported
KitKat[12] 4.4–4.4.4 October 31, 2013 19–20 Supported;[13] See clarification Restriction for applications when accessing external storage, except for their own directoriesStorage Access Framework, an API allowing apps to retrieve files in a consistent manner. As part of the framework, a new system file picker allows users to access files from various sources (including those exposed by apps, such as online storage services).
Lollipop[14] 5.0–5.1.1 November 12, 2014 21–22 Supported Third-party applications regain the ability to read and modify data located anywhere on external storage, such as on SD cards.
Marshmallow[15] 6.0–6.0.1 October 5, 2015 23 Supported Adoptable External storage to behave like Internal Storage
Nougat[16] 7.0–7.1.2 August 22, 2016 24–25 Supported 7.1 - Manual storage manager – identifies files and apps using storage
O 8.0 TBA 26 Beta

Resources

Partitions

Android OS has different partitioning setups. Among them you should find:

  • /system
  • /data
  • /cache
  • /sdcard
  • /sd-ext
  • /recovery - is the application that helps with the recovery of the android. Recovery apps are

Resources

Clone this wiki locally