I just tried something to free up some space for shared data/sdcard partition by moving Dalvik Cache from /data to /system then creating a folder link back in data to keep original location settings.
Took 30 seconds and freed up 260mb! This is what you do:
1. Using root explorer or similar. Go to /Data.
2. Navigate to "Dalvik-Cache" directory. Long press on it and select "move".
3. Navigate back to root directory and then to /System.
4. Paste the directory you must select rw first top right hand corner. It will take a minute to copy.
5. Now long press on the moved Dalvik-Cache directory in /System and select "Link to this folder" option.
6. Navigate back to /Data and paste the link.
7. Done! You now have moved the Dalvik-Cache location to unused space on System partition and left a sym-linked directory so Android thinks nothing has changed!
Note!: If you wipe Dalvik Cache from recovery a new directory will be recreated in Data and your moved directory in System will no longer be used it will just sit in System taking up space.
AFTER A DALVIK CACHE WIPE FROM RECOVERY YOU MUST DELETE THE DIRECTORY YOU CREATED IN SYSTEM AS IT IS NO LONGER USED. SIMPLY REPEAT THE ABOVE STEPS TO ACTIVATE THE MOD AGAIN.
Good luck. A REAL Dev could you please turn this into a CMW zip with the reverse undo counterpart to be flashed before a Rom upgrade.
UPDATE: looking at the link posted by a helpful person below (thanks!) I think we need to make /system mount as rw for this to work. Please help develop this idea more if anyone can help thanks
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