[MOD][SCRIPT] Get More Storage by Relocating Dalvik Cache!

skyguy126 · Nov 26, 2014

DISCLAIMER: YOU AGREE TO TAKE FULL RESPONSIBILITY FOR YOUR DEVICE IF YOU PROCEED.

The original thread (http://xdaforums.com/moto-g/general/mod-save-data-space-cache-partition-t2942765) was getting to cluttered up with development and testing so I decided to start a new thread with the "finished" product. The original thread will be renamed to Q&A/Development. We might even ask for the old thread to be closed down. (up to @Bert98, the thread's creator.)

Moto G's internal eMMC card has a ~600Mb partition called /cache, which is not used since the apps' cache is stored in /data, so the latter fills up and the first one stays empty.
Owning a 8Gb model, having 600Mb not available for storage really bugged me, because my phone's memory (/data partition) was always full because it's a 5.7Gb space shared between apps and microSD files.

Now, it may not work for you if:
a) you have A LOT of apps installed.
And by "a lot", I mean more than 90-100 apps, but if you have a 8Gb model, you probably don't

b) you're running ART (this is default in lollipop and newer)
Since ART uses a lot more space than dalvik, the space in the /cache partition probably won't be enough. When I was running ART, it used 1Gb more than dalvik.

Original post by @Bert98

This was tested on my moto g 16GB which is running RetailUS_4.4.4 kitkat with CWM recovery. The custom ROM procedure was tested on the same phone but with cm11 Nightly installed.

Prerequisites:
1. You must have "adb root" functioning. If you don't head to this thread: http://xdaforums.com/showthread.php?t=1687590 and there is a free download link at the bottom of the post.
Download and install the apk on your phone. Open up adbd insecure (the new app) and grant it superuser rights PERMANENTLY. Check the box that says "enable insecure binary" and make sure to check the box
that says "enable at boot."
2. You must have a recovery that can accept adb shell commands.
3. Root Access Duh?!
4. A windows machine capable of running batch files.
5. A decent text editor, notepad will work but notepad++ is strongly recommended. (Only needed if you are using STOCK ROM procedure)

Please, please make a nandroid backup before you continue!!!!

Stock ROM procedure:

Custom ROM procedure:
USE THIS FOR ROMS THAT DO NOT REMOUNT OR CHANGE PERMISSIONS OF /CACHE ON BOOT

If anything goes wrong:

Custom ROM procedure already has a restore script!

I am currently working on an auto restore script for stock and that will be relased soon, hopefully! :good:

Changelog:

How it works?!?!

Huge thanks to @Bert98 and @dd043
Hit the thanks button if it worked! I went through about 50 factory resets, and reflashed the ROM about 25 times, and put about 10 hours of work into this script! Really motivates me for future projects. :laugh:

AndroidHtc101 · Nov 26, 2014

Thanks for your help man and effort.
I encountered a problem, everything works up until my device boots in CWM to fix permissions, then just sits there doing not alot

I don't even see the option in my CWM.

Any ideas? cheers

Sent from my XT1032 using XDA Free mobile app

skyguy126 · Nov 26, 2014

When it reboots to cwm unplug the cable and replug it, if it hangs just type these commands manually from a command window.

chmod 655 /cache
chmod 655 /cache/dalvik-cache
chmod 655 /cache/dalvik-cache/*
reboot

If this does not work you may ned to go into mounts & storage in the cwm menu and click mount /cache. Then try the commands again.

dd043 · Nov 26, 2014

I'm having some issues on stock.

I thought 0655 fixed everything but no, I can't install any app after moving the dalvik-cache to /cache. I tried chmoding 0777 on the new cache folder, on /cache itself, to no avail.

Code:

E/dexopt cannot open '/data/dalvik-cache/app@....dex' for output

Anyone can confirm it's not only my device? And/or can help find a fix?

Also does someone knows how to execute commands on a particular init step? Real init.rc scripts can do:

Code:

on post-fs-data
     mount -o bind /cache/dalvik /data/dalvik-cache

It there was a way to achieve the same from post_boot/init.d we could mount -o bind /cache/dalvik /data/dalvik-cache and all permissions issues would disappear as well as the need for symlink.

Vuciz · Nov 27, 2014

You have a typo in the threads title. Just a heads up.

skyguy126 · Nov 27, 2014

Vuciz said:
You have a typo in the threads title. Just a heads up.

Thanks for letting me know!

skyguy126 · Nov 27, 2014

dd043 said:
I'm having some issues on stock.

I thought 0655 fixed everything but no, I can't install any app after moving the dalvik-cache to /cache. I tried chmoding 0777 on the new cache folder, on /cache itself, to no avail.

Code:

E/dexopt cannot open '/data/dalvik-cache/app@....dex' for output

Anyone can confirm it's not only my device? And/or can help find a fix?

Also does someone knows how to execute commands on a particular init step? Real init.rc scripts can do:

Code:

on post-fs-data mount -o bind /cache/dalvik /data/dalvik-cache

It there was a way to achieve the same from post_boot/init.d we could mount -o bind /cache/dalvik /data/dalvik-cache and all permissions issues would disappear as well as the need for symlink.

Let me try and do that right now... Ill get back to you if it does!
My script works on stock btw... But the mount way seems a bit easier and might cause less errors than my way.
Try it please.

dd043 · Nov 27, 2014

skyguy126 said:
Let me try and do that right now... Ill get back to you if it does!
My script works on stock btw... But the mount way seems a bit easier and might cause less errors than my way.
Try it please.

Yes I've tried your script, all went well but the result is the same. The script itself works nicely btw

Applications present before moving cache work perfectly, but I can't install anything new. I suspect it might be my device but before wiping everything I'd prefer feedback from others :fingers-crossed:.

skyguy126 · Nov 27, 2014

I cannot install new apps as well. The mount command you showed me has the same effect too. I honestly don't know anymore, the sym link did not allow the install of new apps nor did the mount command you sent me. Correct me if I am wrong.

Edit: Going through all the init files on my phone to see which one remounts /cache at boot.

skyguy126 · Nov 27, 2014

Why does the init.rc get overwritten at boot. Is it because the kernel (boot.img) is the one that copies it over? I have found by changing the perms/locations in this file and init.target.rc you can achieve what this mod is trying to acomplish.

AndroidHtc101 · Nov 27, 2014

I don't see the mount cache command in CWM strange

I've managed to get back to normal, thanks for everyone's help though, I will keep and eye on the thread

Sent from my XT1032 using XDA Free mobile app

zarac · Nov 27, 2014

non-windows version?

Thanks for this tool. It's a great idea and our Motos really need it.
However, I have a problem - I do not own a windows license (os x and ubuntu user) and I would prefer not to spend $120 just to use it for this script. Pirating is out of the question for me.

I was wondering if there is any chance of having this script written for linux and/or mac. If impossible, is there a LEGAL way of running windows in a virtual machine? Something like a trial or similar?

skyguy126 · Nov 27, 2014

If you know how just convert it to shell script for osx and Linux. I give you permission to do this but you may not take credit or rehost your creation.

skyguy126 · Nov 27, 2014

Ok so I have the kernel extracted and we could modify and flash that, but I believe that it's not really necessary. There are a lot of risks to flashing kernels and I am not willing to take it. So is there a way we can modify dalvik so it creates it's cache in /cache instead.

dd043 · Nov 27, 2014

skyguy126 said:
Why does the init.rc get overwritten at boot. Is it because the kernel (boot.img) is the one that copies it over? I have found by changing the perms/locations in this file and init.target.rc you can achieve what this mod is trying to acomplish.

Yes the init.rc is in the boot ramdisk. I don't think it would be worth the trouble to rebuild a boot.img. The moto g is fairly unbrickable but it's quite a lot of work to setup an environment to rebuild an image :/.

Too bad for the mount command, I was sure it was working but maybe I had changed something else and don't quite remember the steps to reproduce

We could possibly implement a shell script toggler for when we need to install new apps, but I'm afraid it'd become annoying fairly quickly: I noticed the issue initially because google play services decided to update itself, failed, and broke all google apps. As far as I know this autoupate can't be disabled.

Thanks for trying!

skyguy126 · Nov 27, 2014

dd043 said:
Yes the init.rc is in the boot ramdisk. I don't think it would be worth the trouble to rebuild a boot.img. The moto g is fairly unbrickable but it's quite a lot of work to setup an environment to rebuild an image :/.

Too bad for the mount command, I was sure it was working but maybe I had changed something else and don't quite remember the steps to reproduce

We could possibly implement a shell script toggler for when we need to install new apps, but I'm afraid it'd become annoying fairly quickly: I noticed the issue initially because google play services decided to update itself, failed, and broke all google apps. As far as I know this autoupate can't be disabled.

Thanks for trying!

How about making a simple apk that toggles this feature. Something like when you click the icon it doesn't even open but gives a little notification of success. Something like that. I myself am not experienced with apks but I can put together a shell script for the apk.

dd043 · Nov 27, 2014

skyguy126 said:
Ok so I have the kernel extracted and we could modify and flash that, but I believe that it's not really necessary. There are a lot of risks to flashing kernels and I am not willing to take it. So is there a way we can modify dalvik so it creates it's cache in /cache instead.

Patching dalvik itself sounds promising. It can probably be done with in a batch script with a command line hex editor.

The path is defined in frameworks/base/cmds/installd/installd.h

Code:

#define DALVIK_CACHE_PREFIX    "/data/dalvik-cache/"

Not sure if there is another mention in the source tree.

But there's nothing to say we wouldn't face the same issue, the error message in the logcat is pretty generic

skyguy126 · Nov 27, 2014

dd043 said:
Patching dalvik itself sounds promising. It can probably be done with in a batch script with a command line hex editor.

The path is defined in frameworks/base/cmds/installd/installd.h

Code:

#define DALVIK_CACHE_PREFIX "/data/dalvik-cache/"

Not sure if there is another mention in the source tree.

But there's nothing to say we wouldn't face the same issue, the error message in the logcat is pretty generic

Ill try it. I don't mind doing a bunch of resets because I am using my moto g as a test bench anyway. My daily driver is the OnePlus One

skyguy126 · Nov 27, 2014

dd043 said:
Patching dalvik itself sounds promising. It can probably be done with in a batch script with a command line hex editor.

The path is defined in frameworks/base/cmds/installd/installd.h

Code:

#define DALVIK_CACHE_PREFIX "/data/dalvik-cache/"

Not sure if there is another mention in the source tree.

But there's nothing to say we wouldn't face the same issue, the error message in the logcat is pretty generic

EDIT: Unfortunately it didn't work. I don't know if I modified the installd file correctly. The program I used is HxD.

skyguy126 · Nov 27, 2014

Is there a way we can force dalvik to start after the directories are created. And change dalvik to create it in /cache.

[MOD][SCRIPT] Get More Storage by Relocating Dalvik Cache!

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