Skip to main content

Freeing up phone storage with Link2SD

Another more powerful way of freeing up phone storage is with Link2SD. Using this method requires you to have a rooted phone. If you don't, either root your phone or there isn't really much else you can do.

The idea behind Link2SD is simple. Remember Android is basically a modified version of Linux and the application files resides in /data (where '/' , or the root directory, is your phone storage). When more and more files are created in /data, your phone storage is slowly eaten up and very soon you will see the "Phone storage low" warning.

Link2SD lets you move some of the files in /data to the SD storage but retain a pointer or symbolic link in /data. This is a legitimate filesystem sleight-of-hand that retains the directory structure that Android expects, but with the bulk of the data moved to the SD card.

For example, after moving Angry Bird using Link2SD, the affected files are:

/data/app/com.rovio.angrybirds-1.apk -> /data/sdext2/com.rovio.angrybirds-1.apk
 

/data/data/com.rovio.angrybirds/lib/libangrybirds.so -> /data/sdext2/data/com.rovio.angrybirds/lib/libangrybirds.so
 

/data/dalvik-cache/data@app@com.rovio.angrybirds-1.apk@classes.dex -> /data/sdext2/dalvik-cache/data@app@com.rovio.angrybirds-1.apk@classes.dex

As you can see, the symbolic links point to a special partition on the SD card that is mounted as /data/sdext2.

Installing Link2SD is very simple. Before installing, create a second partition on your SD card. You can use a non-destructive partition manipulation tool such as MiniTool Partition Wizard to create the second partition. Depending on your needs, a partition size of 512MB to 1024MB should be sufficient. You can always increase the partition size later if necessary.

Now find Link2SD on the market and install it. After installation, reboot your phone. This will allow Link2SD to mount the partition. Now you are ready to use Link2SD. Launching Link2SD will bring you to a list of all the applications on your phone:


From there, you can choose which apps to link to the SD card. Apps which are already moved using Froyo's native A2SD method cannot be moved. You need to move them back to phone storage before you can run Link2SD on them.

I find a couple of menu functions rather useful. Under "Filter", you can choose to see only those apps that have not been linked ("Not Linked User"). Sorting that list in decreasing order of "Apk+Dex+Lib Size" using the "Sort" function will give you the top candidates for linking to the SD card (i.e. those apps that are using the most phone storage).

I also like to use Link2SD exclusively, so by using Move2SD Enabler to set the default installation location to "Internal", I don't have to deal with Froyo's A2SD mechanism again. You can also enable the "Auto link" function under Link2SD's "Settings", which will automatically link any newly installed app to the SD card. However, I did not enable this because I like to have more control over which apps I link to the SD card. Also remember that you should not link widgets, input methods, live wallpapers etc. to the SD card.

The limitation with Link2SD is that you cannot link system apps to the SD card. However, the author is working on this and this should be possible in a future release. Also, a future version may allow you to disable A2SD directly without using another app.

In summary, Link2SD is a pretty powerful tool for freeing up phone storage by linking application files to the SD card. You get a nice GUI for linking/unlinking application files, fine-grained control over which files to link (apk, dalvik cache, library files) if you wish, a set-and-forget option to automatically link applications to the SD card. All you need is a rooted phone, a few minutes to create a second partition on your SD card, and a few more minutes to install Link2SD, reboot and do a bit of linking. With minimal effort, you should never have to see the "Phone storage low" warning again.

Comments

  1. Very neat explanation. Best I've seen in my search to figure out whether I save more internal memory space by moving an app to SD or leaving it on phone and linking to SD. Well onward I go searching or not be so lazy and test the scenarios myself :-)

    ReplyDelete

Post a Comment

Popular posts from this blog

Cooling mod for the X96 Air #2

Previously, I added a USB cooling fan to the X96 Air TV box . The problem with this mod is that the fan is always running, and it runs at full speed. Ideally, the fan should kick in only when the CPU temperature is above a certain threshold. It would be even better if there is a way to control the fan speed. Dan McDonald left me a comment pointing to his project on Github . He basically connected the fan to a USB relay that can be controlled by Python script. His project inspired me to make a similar mod that would make use of the spare D1 Mini boards I have lying around. The plan is to hook up the fan to a MOSFET (2N7000) and control it via PWM. Here's the very simple circuit: The code simply reads a single character from the serial port (0 - 9). 0 will turn the fan off, while 1 - 9 will generate a proportional PWM to drive the fan, with 1 being the lowest and 9 being the highest. Here's the Arduino code: #include <Arduino.h> void setup () { Serial . begin ( 9600 ...

Installing and customizing CoreELEC in X96 Air

I previously installed CoreELEC on another TV Box ( Ugoos X3 Pro ), which unfortunately died after only 9 months during the summer (due to the unit overheating, which I learned is a common problem for cheap Android TV boxes). So this time I purchased a X96 Air  (4GB/32Gb) and had to do the whole thing again. So this is a note-to-self in case I ever have to install CoreELEC again on some other device. Installation of CoreELEC is simple enough by following this guide . Basically, it involves downloading and writing the firmware to a microSD card using usbimager . Then insert the microSD card, reset the unit and hold the reset until the logo appears. The unit will then proceed to boot into CoreELEC. First thing is to connect to WiFi, then enable SSH. This allows me to login via ssh and execute: ceemmc -x from the terminal. This writes CoreELEC to the built-in eMMC storage, after which I am able to remove the microSD card and reboot the unit into CoreELEC via the built-in sto...

DC-DC Buck Stepdown Converter for ESP8266

I am working on a project that requires a step-down converter from 12V to 5V, that will then power a WeMOS D1 Mini. I saw this new mini buck converter based on the usual LM2596 MP2307 , so I thought I'd give it a try. Unfortunately, it didn't work. Although it is supposed to be able to supply up to 1.8A, the D1 Mini was not able to boot up. The 5V pin was being properly supplied, but the 3.3V pin measures at only ~1.3V. So I had to go back to my usual LM2596 module, which is much larger, but works to power the D1 Mini with a 12V source. Here's a great review of the mini buck converter I found while trying to figure out how to make it work. The fact that it has high quiescent current (~60mA) is also mentioned in a few other sources.