While editing the vold.fstab file works well enough for completely swapping sd & extsd mounts,it an absolute pain if updating to a new rom - everything defaults to normal & the procedure has to be done again - its I would say a pretty extreme measure to get full use of your extsd card storage - although the benefits are that you can install literally anything to extsd rather than the internal 8gb memory - it comes with some risk as you are infact editing a very important system file
Ive been having a play around with Gl to SD (free app from the play store) & can confirm it works 100% on the latest cm9 rom & kernel
This program (many old galaxy s2 owners & many other android phone owners that have owned phones with internal flash memory will already know of it) allows you to copy any app/game data that is stored on the internal 8gb flash to external sd & mount inside the gl to sd app itself ,it doesnt change any of the system files & is 100% safe
This will work with any app (mainly games) that store large amounts of data inside the android/data folder on the internal 8gb flash & also any gameloft game that uses the gameloft/games directory
I had a few gameloft games that were taking up huge amounts of space on the internal 8gb
namely these few - NOVA 3 (1.77gb) , Lets Golf 3 (777mb) ,mass effect 3 infiltrator (583mb) , Asphalt 6 (911mb), Blood & glory (625mb)
This left me with literally a few hundred mb to spare !!
I have now moved all this data to my ext 32gb microsd card (nearly 5 gb of data ) & the games are working fine
Did this first with a class 4 8gb card to test - it worked ok but some of the load times were very very slow
Now using a class 10 32gb sandisk & it is very nearly on a par with the speed of the internal flash memory & I have literally all of my 8gb (well more like 5gb which is available) back
There is also an app called directory bind (I have only had partial success with this one) it worked for a while then tended to corrupt directory structures (it mounts automatically on boot) which lead to a lot of games asking to redownload all the gamedata numerous times when run - hence the recommendation of gl to sd
A lot of people have been asking about using the extsd for app installation - this is about as good as it gets without modifying the boot image or editing the vold.fstab file
Im finding at the moment that the 8gb memory is pretty much good enough for small apps,its only the big games with data downloads that take up huge amounts of space,& along with a 16 or 32gb card I reckon I can now live with it