Clear your doubts guys!!!
Ok, so here's the deal, in a very longwinded way that should hopefully explain everything and answer ALL questions.
You have an SD card in your phone and, a bit like normal PC Hard Drives, you can "partition" them (split them into two or more sections of different filesystems). Normally, your SD card is just one big FAT32 partition, which is fine for storing your pics, messages, emails, etc.
Now, other then your Phone's SD card, your phone will have its own internal flash memory (or "NAND") storage. Tradditionally with Android, you could only install applications to this NAND storage, you cannot install them onto your SD card. So if you have an empty 32GB SD card, but only 5Mb of internal phone storage, you still wont be able to install many apps, if any at all.
This was done to protect the apps from things like piracy - it's not easy to access the location where apps are installed on your phone's internal storage (normally impossible without root), so you can't for example buy an app, copy it, refund it, then install it again.
Still, this is no good for those of us who like to install lots and lots of apps, legitimately, as we run out of internal storage very quickly.
So Google came up with a way to install apps to the SD card. A folder is created called something like .android_secure and this stores (I believe) encrypted versions of applications, but there's a few catches:
1) Apps aren't automatically stored here, you have to manually "move" them
2) Not all apps are capable of being moved, in fact most apps aren't, the developer needs to update their app and allow it. Some apps aren't and wont be updated and some developers may not want to allow it for whatever reason.
3) Not all app data is moved, most of it is but some data is left on your phone so many people still run out of internal storage quickly.
4) You can force ALL apps to be moved to this area by default, but it breaks incompatible ones - such as Widgets, which are unable to load due to the SD card not being "prepared".
So that's Froyo's version. Before Froyo existed, some very clever people came up with a thing called "Apps2SD". Remember I said that your SD card normally is one big FAT32 partition? Well, Apps2SD works by having your SD card patitioned into TWO filesystems. A normal FAT32 partition for your usual stuff and a secondary "EXT" partition. EXT is just a filesystem, like FAT32 or NTFS, but it's the filesystem used by Android internally. The SD card is normally FAT32 because it's a "universal" filesystem, that just about any machine will be able to read, whereas EXT filesystems are generally Linux only, but I digress.
EXT has several different versions. The most common one you'll see is ext3. The main difference between ext2 and ext3 is "journaling", which is just a fancy way of saying that should an operation (such as copying, writing or reading) be interrupted unexpectedly (say, by you turning your phone off), then no data should be lost or corrupted. You know how when you turn your phone on, it says "preparing SD card"? It takes a few minutes, but what it's actually doing is checking that the FAT32 partition hasn't been damaged, because FAT does NOT have journaling. If you used a computer back in the Windows 98 days, you may remember that lovely blue "Scandisk" screen that had to run every time you didn't shut your computer down correctly - that's the same thing. But then Windows 2000/XP came along with NTFS, which also has journaling, meaning you had less chance of loosing data. But I digress once more.
So you have your SD card partitioned into EXT and FAT32. Generally it doesn't matter if it's ext3 or ext4, but you don't get any real advantage with ext4 over ext3 in this instance. Apps2SD then runs a special script on your phone which "symbolically links" the folder from your phone's internal storage where your apps are normally stored, to the ext partition on your SD card. A symbolic link is a bit like a shortcut for folders, except it's transparent to the OS: In other words, Android doesn't know that when it's installing it's apps to the internal phone storage, it's actually being stored on the SD card. This effectively boosts your internal phone memory from the previous 5mb that you had in my example above, up to whatever size you made the ext partition on your SD card (often 512Mb or 1Gb, but it depends on how many apps you install).
Plus, because it's "journaled", it doesn't need to be "prepared", meaning it's ready to go as soon as the phone starts - so your widgets and apps work immediately (unlike "forced" Froyo Apps2SD, where widgets disappear).
The catch with Apps2SD is that whatever space the ext partition takes up is taken away from the SD card. So if you have a 4Gb card (with something like 3.5Gb of actual storage) and you make a 512Mb ext partition, your SD card will "shrink" to 3Gb. The space isn't actually lost, it's just being used by the ext partition. If you reformat your card, you'll get it back.
Finally, there's a difference between "Apps2SD" and "Apps2SD+". Remember I said that your apps are stored on a special folder inside your Phone's NAND storage? Well, that was a bit of a lie. It's actually stored in TWO places. There's a second area which is called the Davlik Cache. You don't really need to worry about what this is for (Hint: IT's to do with the Java runetime your phone uses to run apps), all you need to know is that apps use it to store data, which also eats up internal phone memory. Apps2SD+ moves davlik cache to the ext partition on your SD card as well, freeing up even more space. Some people believe that this may come at the cost of performance, as the internal NAND memory should be faster than your SD card (Which is why you also get people arguing over which "class" SD card is better for Apps2SD - the logic being that a faster SD card means less impact from this move), but the truth of the matter is that your applications will be running from your Phone's RAM anyway, so performance isn't really impacted at all. Since most apps are only a few hundred Kb's in size, or a couple of MB at the most, it's a non-issue.
Finally, any recent version of Apps2SD/Apps2SD+ should work with an SD card that is or isn't formatted with an ext partition. It'll check for this partition when your phone first boots and if it's not there, just use internal phone storage.
Having an ext partition WITHOUT Apps2SD+ shouldn't cause any issues, either, so you can format your SD card whenever you're ready.
So in summary:
Apps2SD "fakes" your phone's internal memory and puts it all on a hidden section of your SD card.
Apps2SD+ pushes even more content to the SD card, freeing up even more space on the phone itself.
"Froyo" Apps2SD has various limitations that "old" apps2SD does not, but is much easier to handle as it doesn't involve any kind of "partitioning".
IF U LIKE HIT THANKS​
Good idea, mate
I have so many apps installed on my SD card using the builtin Gingerbread apps2sd that when I start my phone or switch from USB disk drive mode I can't access my SD card apps for about a minute or so while Android checks the SD card (or so I'm assuming).
Will switching to an Ext partition on my SD card make startup faster? It drives me nuts that when my phone reboots (which it tends to do when it overheats) it starts up pretty quick but I can only access the apps on the phone for the first minute or so.
Btw, I'm running CM7.1 nightly 213 for the Evo. Thanks!
Bump ... anyone have any experience?
To answer my own question, a resounding YES
I partitioned my SD card with Paragon Partition Manager using resize so I didn't lose data and formatted the new partition ext4. I used S2E which made the process super simple, although I had to move all of my SD card apps back to "internal phone memory" (now pointing to the sd-ext partition), but Titanium Backup made that batch job easy. Starting up apps are accessible MUCH quicker and I don't have to worry about widgets and keyboards being screwed up due to being on SD. DO IT!
hi guys,
I partitioned sd card ext with 1GB with FAT32 using mini partion tool
when boot ON the Phone & using with LINK2SD Main sd card & ext sd card showing the same size of 1GB ....
is the problem with ROM ??
I tried with another sd card but the issue is same
i'm using stock rom & 16 GB Sandisk C10 sd card
Pls help me......
Link2SD
The XPERIA X10i running GB 2.3 is a bit problematic with partitions.
The OS only mounts the first partition it finds and that's normally the second partition. Doh!!
The following patch may be of some help to you
SE2.3.3-link2sd-patch.zip
It is assumed you have formatted both partitions as primary.
Everybody should use Link2SD if they have an XPERIA X10, just because most quality class6/class10 cards have better read/write speed than internal flash and with a 1-2GB sdext2 partition more space too.
Considerations
I'd format the second partition as ext3 and 2GB if Link2SD is to be used, especially if a gamer.
I would only use a class6/class10 'quality' 32GB microSD card or greater.
Copy the contents of the /data/sdext2 partition to a NAS/external server
(1) I'd format the partition to be used with Link2SD as ext3 ( I've found on my builds I can't use ext4, but would, if I could ), just because it'll give better performance. In a gaming environment 1GB can be used up pretty quickly if libraries and data are linked too.
(2) The cost of quality class6/class10 microSD cards has really dropped in price now that extreme and extreme pro cards (50MB+ write) are all the rage. It's just a pain having to rebuild a working Link2SD environment onto a larger card at a later date, when a lesser card, no longer meets needs.
But given I'm using a 64GB card, I would say that.
(3) If you copy the contents of the second partition to a linux system /folder it makes a great recovery, as you only have to restore the Link2SD second partition and you get all your apps back, data and all. I copy my /data/sdext2 partition onto my NAS every now and then and it has saved my bacon a few times when microSD/SD cards have gone belly up.
So, I have a samsung galaxy young s6312, stock android 4.1.2 jellybean, rooted. Since the internal memory is very low, I use link2sd to link app files to my external sd card. Now I have created an ext2 partition of 1.5 gb to use with link2sd. but now the partition is full, and my internal memory is also full, because I have installed about 3gb of apps in my phone, half are in the second partition, and half are on my internal memory. so now I want to know if there is a way I can increase the size of my second partition. if I had enough memory, I would have moved the apps to my internal memory temporarily, but I don't have enough internal memory to move the linked apps to my internal memory. so is there any way to increase size of second partition without formatting it?? NOTE: I don't have any problem in formatting the first partition if necessary, but I can't format the second partition. NOTE: the sd card I use is of 8 gb...
Thanks...........
I have the same issue...
... so I'm disappointed to see that no one has replied.
I have a rooted LD-D520 with Android 4.1.2. Since I quickly ran out of memory I added an 8GB SD card and partitioned it with a 1.5GB ext2. I used Link2SD to them move over most all my apps. I don't have that many, but some of them have gotten so big (FB, Skype, etc.) that I now have only 5% free space on the ext2. I don't have much space left on the internal memory either, so I thought I'd try to make the ext2 partition bigger. (There's lot of free space on the SD card since I'm not using much of the other partition.) I tried using the MiniTool Partition Wizard, but even after reducing the size of the non-ext2 partition to create some unallocated space I was still unable to resize the ext2 partition.
Any suggestions? Is there an easy way to do this?
hello
i have rooted note GT-N7000 , 16 G SD card with FAT32 & Ext2 partion , running jealy beans , & use link2sd to overcome internal memory limitation (most of app is in ext2 partition
suddenly , my phone keep restarting , if i remove the sd card or insert new one , it operate normally .
I tested the sd card on my pc , i can access both partion with no error
now the phone runing normally without the sd card or with new sd card, restart happened when i try to open app manager in setting
is there any way to fix this problem in order to be able to access apps on sd card normally