Database Users

[TUTORIAL] Everything you wanted to know about app2sd, ext3, ext4 partitions!!

I found this post in some other section!!
i am just giving the same information here for my fellow g3 mates!!
Full credit go to neoKushan
here the original thread!! http://forum.xda-developers.com/showthread.php?t=742351
Nows here what we are here for!!! 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".

I don't really claim to be an expert but I wrote this and nobody really chimed in to say anything was wrong, so hopefully it applies here.
I'll try to keep an eye on this thread in case anyone has questions.

I don't really claim to be an expert but I wrote this and nobody really chimed in to say anything was wrong, so hopefully it applies here.
I'll try to keep an eye on this thread in case anyone has questions.
Click to expand...
Click to collapse
Thanks a lot buddy.. People may know all that but you have written in such a simple manner that even a small kid will understand..
Acid lestitious 2.0. Fugumod 2.2 build 1.9

thanx soo muxh for this info...it's getting really confusing out there with everyone claiming this type is better than that blah blah blah etcetc....this is very helpful
thanks again

JohnstonF said:
thanx soo muxh for this info...it's getting really confusing out there with everyone claiming this type is better than that blah blah blah etcetc....this is very helpful
thanks again
Click to expand...
Click to collapse
You're welcome
Acid lestitious 2.0. Fugumod 2.2

[Q] Different partition sizes in CM7 SD installer

Hi. Did my usual +3 hours googling but came empty handed.
Could size-agnostic CM7 SD installer script be modified so that /Data partition is set to 2Gb instead of 1Gb? I know that I can always do the "move to SD" routine but Android keeps bugging me that I`m out of space even when I have 170Mb free on /data. And also moving apps back and forth from internal to SD somehow wrecked my system process. As a result I now have constant rebooting of the launcher as my only Android experience. Uninstalling recent apps did not work. Neither did freeing up space on SD and denying root to all apps that previously asked for it.

zuzka said:
Hi. Did my usual +3 hours googling but came empty handed.
Could size-agnostic CM7 SD installer script be modified so that /Data partition is set to 2Gb instead of 1Gb? I know that I can always do the "move to SD" routine but Android keeps bugging me that I`m out of space even when I have 170Mb free on /data. And also moving apps back and forth from internal to SD somehow wrecked my system process. As a result I now have constant rebooting of the launcher as my only Android experience. Uninstalling recent apps did not work. Neither did freeing up space on SD and denying root to all apps that previously asked for it.
Click to expand...
Click to collapse
If you are willing to start from scratch you can burn the image again to the SD, but don't put any zips in it. Boot and let the script create the new partitions. Then put the card back in the PC and use Mini-Tool Partition Manager to shrink partition 4 (sdcard) and grow partition 3 (data) That program will handle the ext partition (3) as long as there is no data written to it yet. You can get that program free on the internet. Do a Titianium backup of your apps and data and restore later.
Edit: Now after thinking about it, you may be able to doctor your existing card. Partition 4 is fat so you can shrink it with data in it. Take the space off the front. Then I think the program will let you grow partition 3 into the empty space even with data already in it. It is just trying to move it with data does the program balk. Windows does not know how to read ext. Of course if you are running linux, just use gparted to do everything.

Yes, you could do that or you could use a program like easeus partition manager and move the partitions around after the first boot of the card.
Edit (while typing): It looks like you might be talking about an internal installation in which case you don't need to use size agnostic SD installer. Just repartition the internal the way you want it (there are threads for this) then flash your CM7.
Edit 2: beat out by leapinlar while editing 1
JP

Thanks for the idea of repartitioning prior to installing CM7. I`ll also try to repartition SD the way it is now- with data. I was concerned that /data partition is unmountable under Ubuntu when /boot and /system can be read without problems.
Hi again. I`ve managed to srink /sdcard partition under Windows and sort of grow /data partition under Ubuntu LiveCD (gparted froze right after doing its magic).
Boot loop on my Nook stopped as free space on /data increased from 175Mb to 1.2Gb. So I guess I wont be doing a fresh install at the moment.
Question is, exactly how much free space does CM7 need on /data partition? In a real world?
(at ~200Mb it starts bugging me about free space but overall Android stays stable)

zuzka said:
Question is, exactly how much free space does CM7 need on /data partition? In a real world?
(at ~200Mb it starts bugging me about free space but overall Android stays stable)
Click to expand...
Click to collapse
Original Nook Color had 1GB for data. B&N upped it to 5GB on the new Nook Colors. I personally would make it 2GB unless you are going to be adding some really big apps.
Sent from my Nook Color running ICS and Tapatalk

[Q] Apps to EMMC?

So searching thru the threads here it seems that the only way to utilize the EMMC memory on the Nook Color is to repartition the NC so that it all looks like internal phone memory? Is this correct or has there been a way found to utilize both the EMMC memory area AND the SD card?

Not sure what you are asking specifically but you do not have to repartition the Nook to look like internal phone memory to use the internal memory.
1. You can use the internal memory stock or rooted and you can repartition the internal memory so that the system and data allocations are to your preference. Typical partitioning is 1GB system and 5GB data. Plus whatever size SD card you insert.
2. You can install a custom ROM and the use of internal memory is the same as above with the standard being 1/5GB. Plus whatever size SD card you insert.
3. You can run a ROM on a bootable SD card where the ROM sees 1GB of the card as "internal memory" (also some space is used for the system and ROM) and the rest of the space on the card is seen as "SD card external memory." You can also mount the data partition of the Nook's internal memory so that the bootable ROM on the SD card also sees another data partition of 5GB. This is handy for items you want to appear to both the Nook's internal ROM and the ROM on the bootable SD card.
JP

I'm not clear what you are asking either. Before I repartitioned I had 1/5 and ran apps that I worried about load times on from eMMC. Stuff like flashlight or aldiko that I don't sweat that much I loaded from the SD card. Because I felt the 5 was going to waste I flipped it to 5/1. Now I ignore the loss of the 1, load everything I run to the 5 and have 32 to store books, movies, music or whatever on. (Technically I could make use of the 1 if I wanted to but it's not worth it to me.)
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Sent from the Center of My Mind

I have 5 gig sitting there doing nothing in EMMC partition. I would like to be able to access this memory as well as the external 8 gig card i have in it. Right now the space on the EMMC partition never gets touched.
So will the nook start to auto install to the EMMC partition if I fill up the one gig partition? or is it just going to sit there unused.

shadoes said:
I have 5 gig sitting there doing nothing in EMMC partition. I would like to be able to access this memory as well as the external 8 gig card i have in it. Right now the space on the EMMC partition never gets touched.
So will the nook start to auto install to the EMMC partition if I fill up the one gig partition? or is it just going to sit there unused.
Click to expand...
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Except if you changed something in settings, the original installation place is the EMMC.
In case you fill all this space there, then you will have to start installing apps to SD.
For me there is no reason to install directly to EMMC, except if some app only runs from there and therefore should be installed only there (like widgets).

after the install of CM 7.2 the auto setting places apps in the 1 gig partition and apps2sd moves them to the 8 gig external card. the 5 gig EMMC partition is completely untouched.
If I fill up the 1 gig partition will they move to the EMMC? if not it appears this space will be completely wasted. I would prefer to use it as that frees up space to put music/media files on the SDcard for road trips.
I only leave apps on the internal memory I want to run faster. I noticed with my phone that once that spot start to fill up the phone runs noticeably slower.

shadoes said:
...
So will the nook start to auto install to the EMMC partition if I fill up the one gig partition? or is it just going to sit there unused.
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Click to collapse
No and Yes. Unless you go to Settings>Cyanogemod settings>Application> check Use internal storage
Then you will lose the SD card and gain the 5G. You can easily go back by unchecking it again whenever you want to. (That's why I did what I did with the partition swappy stuff.)

shadoes said:
I have 5 gig sitting there doing nothing in EMMC partition. I would like to be able to access this memory as well as the external 8 gig card i have in it. Right now the space on the EMMC partition never gets touched.
Click to expand...
Click to collapse
It's there, you can put anything you want in it, the question is whether the apps you use can find the files you've stashed there. Some apps can, some can't.
BeyondPod (RSS feeds) lets you put its storage anywhere you want, so I moved that and my music into /emmc, and Music found the mp3s without me having to tell it anything. I don't buy many mp3s from Amazon, so I don't know how that interacts.
Also, I swap to /emmc, which is still an experiment in progress.
So will the nook start to auto install to the EMMC partition if I fill up the one gig partition? or is it just going to sit there unused.
Click to expand...
Click to collapse
No, it won't do it automatically unless you always use it, like another poster suggested.

To further clarify, once the system partition is full that's it, the only thing else it does is tell you it's full. No rolling over, no starting to install elsewhere.
All Settings>Cyanogemod settings>Application> check Use internal storage does is trick the NC into thinking the internal memory is an SD card. When you have that checked and are loading all your apps to the External memory by choosing Settings>Cyanogemod settings>Application>Install location>External you are loading them to the 5G.
The bad part about it is that you can only use one or the other, if you load a bunch of stuff to the 5G and then switch to the SD card, (uncheck the Use internal storage box), you won't be able to count on the stuff on the 5G to load properly. Same with if you load a bunch of stuff on the SD and change to the 5G.
*I've* chosen to repartition the system partition to 5G and the eMMC to 1G. 5G is so much more that I should ever need for apps it's ridiculous and because I have a 32G SD card I can just forget about the 1G.

I suppose I should repartition but I don't want to have to wipe and reinstall everything.

shadoes said:
I suppose I should repartition but I don't want to have to wipe and reinstall everything.
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Click to collapse
I waited till I had a genuine Sandisk class 4 16G SD. I know you shouldn't have to worry if you aren't booting from it but what the heck.
Oh and Titanium Backup is your friend. It'll even get your wallpaper back. The only thing I had to manually reload was the custom boot animation.

i tried titanium with my phone and it failed horribly haha. but I will try it again. i would like to have access to that space. also need to try loading my mp3s to it via the PC. that may work as well.

shadoes said:
i tried titanium with my phone and it failed horribly haha. but I will try it again. i would like to have access to that space. also need to try loading my mp3s to it via the PC. that may work as well.
Click to expand...
Click to collapse
Download the latest Titanium and backup. If possible save the *.apk file to your SD Card.
http://forum.xda-developers.com/showthread.php?t=1094371 Choose the "c" repartition option. After completing the repartition and format you will have a virgin install of whatever ROM you are running. Either install Titanium from the apk or download it again and do a restore, (note the amount of memory you have at the bottom). If I remember right you have to click install and done for every third party app you have but what the heck, it's better than setting there watching pixels burn. Once the restore is done look at the memory stats in Titanium again and note what memory got used. Reboot one last time and you are done.
As for the mp3's, I do all that kind of stuff through Samba. The only time I plug a wire into the NC is to charge it. I guess you could take the SD card out to do that but I've been given to understand we want to avoid taking that in and out where ever possible as well.

Another alternative to above Titanium BU tip is to sync your BU to Dropbox, zip it and after reinstall of ROM upload your zipped BU file into the SD folder Titanium makes when first installed, unzip, overwrite, and everything's there. I've never had trouble with this method. And it's fast...

Please use the Q&A Forum for questions &
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Moving to Q&A

[Q] Nook Color only shows 800mb of free space in Apps

I have a Nook Color that was deregistered. I never registered it and followed these instructions to boot to CWM, and I then installed the latest Encore CM9 and the CM9 GApps.
When I go into Apps, it shows that there's only around 700mb free.
I installed DiskUsage and it shows /mnt/emmc, /mnt/sdcard, /rom, and [Root required]. /mnt/emmc I'm guessing is the NC's internal memory - it's 5.1gb and full of B&N stuff, Good Housekeeping, etc. I tested by using a manga reader application to see where it downloads by default, and sure enough it saved to the SD card by default.
I'm guessing the rooting directions excluded something or I may have a different version of a NC than I thought. Is there any proper set of instructions I should follow? I just burned the 2gb image to a 2gb microSD card from here, but would that be the root cause of the issue - use a 2gb microSD, only have 2gb available? In any case, I've got that image burned and CWM set up per the same thread's instructions. Do I need to do anything else? Is there some kind of partition tool I have to use, kind of like diskpart on a Windows boot CD to delete and mount partitions on the NC before continuing?

You have everything right. With the older Nook Colors they came with 1000MB set aside for app storage and 5000MB for media storage. Usually the 1000 MB is plenty for apps. You have used about 300MB so far storing installed apps and settings for your system apps leaving you with 700MB left. That is a lot. Apps do not take much room. Media is where you eat up storage, pictures, movies, books, etc.
The CWM card you used does not effect your nook storage.
You can repartition if you want, but your setup works well for most people.

leapinlar said:
You have everything right. With the older Nook Colors they came with 1000MB set aside for app storage and 5000MB for media storage. Usually the 1000 MB is plenty for apps. You have used about 300MB so far storing installed apps and settings for your system apps leaving you with 700MB left. That is a lot. Apps do not take much room. Media is where you eat up storage, pictures, movies, books, etc.
The CWM card you used does not effect your nook storage.
You can repartition if you want, but your setup works well for most people.
Click to expand...
Click to collapse
How hard is it to repartition? I've got around 2gb of manga I copied off my former Touchpad that I was hoping to copy over. I know, the easy answer would be to just buy a bigger microSD card but I wanted to see what I can get out of the Nook itself first.

MJPByron said:
How hard is it to repartition? I've got around 2gb of manga I copied off my former Touchpad that I was hoping to copy over. I know, the easy answer would be to just buy a bigger microSD card but I wanted to see what I can get out of the Nook itself first.
Click to expand...
Click to collapse
It is not really hard to repartition. There is a thread here that tells you how to do it.
http://forum.xda-developers.com/showthread.php?p=14101197
As I said earlier, the original nooks had 1GB for app storage (/data) and 5GB for media (emmc). The newer nooks came with 5GB for apps and 1GB for media. The author of the above thread offers zips to repartition to either scheme and even included a 2GB app/4GB media version.
I don't know what manga is, is it media or apps? You already have the optimum setup for media. A bigger SD is generally used for more media storage. I really think you might not understand how each partition is used. The app partition (/data) only stores the app program itself and some minor settings files. All of the data that a program uses like books, document files, etc. or downloaded things like music, etc are stored on media partitions like the 5GB media partition (emmc) or sdcard. So I'm not sure you need to change anything. You only want to change if you want more room to store many very large programs (not the files they use).

leapinlar said:
It is not really hard to repartition. There is a thread here that tells you how to do it.
http://forum.xda-developers.com/showthread.php?p=14101197
As I said earlier, the original nooks had 1GB for app storage (/data) and 5GB for media (emmc). The newer nooks came with 5GB for apps and 1GB for media. The author of the above thread offers zips to repartition to either scheme and even included a 2GB app/4GB media version.
I don't know what manga is, is it media or apps? You already have the optimum setup for media. A bigger SD is generally used for more media storage. I really think you might not understand how each partition is used. The app partition (/data) only stores the app program itself and some minor settings files. All of the data that a program uses like books, document files, etc. or downloaded things like music, etc are stored on media partitions like the 5GB media partition (emmc) or sdcard. So I'm not sure you need to change anything. You only want to change if you want more room to store many very large programs (not the files they use).
Click to expand...
Click to collapse
Manga's Japanese comics, so in this case media.
In the repartition thread, would I be using the 1.1 "old" partition zip? And am I just booting to a CWM SD card and running the zip after backing up the device? Or is there a different set of steps since it's a rooted device already?
I may give it the test of time and see if I do need to futz with the partition table after all, but if I do I'd like to have the basics ready to go.

MJPByron said:
Manga's Japanese comics, so in this case media.
In the repartition thread, would I be using the 1.1 "old" partition zip? And am I just booting to a CWM SD card and running the zip after backing up the device? Or is there a different set of steps since it's a rooted device already?
I may give it the test of time and see if I do need to futz with the partition table after all, but if I do I'd like to have the basics ready to go.
Click to expand...
Click to collapse
From what you said in your first post you already have the old partition scheme. No need to change anything. Anything you do will give you less media storage space which is what you need for your comix.
You do not need to be rooted. All you need is the ability to boot to a CWM card and backup and flash things.

Can we mount ext partitions?

Hello all,
Now that we have root on our aesthetically unique device, I believe our next problem is storage space. I don't know about you all, but my aquos crystal has about 4 gb to work with when it comes to apps. Folder mount works well for me, as far as linking the obb files of large apps to the external sd card, but I still have to store a portion of any particular app on the phone's internal storage, which for me is no bueno. There has to be a better way. (For the sarcastic among you, buying another phone is not an option for me.)
Back in the day of Gingerbread, I remember having a whopping 300 mb of app storage to work with. I was able to partition a portion of my external sd to be used as internal storage for the device, solving all my storage woes. It worked so well, that I was sure that I would be able to find a similar method for the aquos crystal.
Now, I see that Link2sd is able to work with ext2, ext3, ext4, and fat32 partitions, so I figured I would attempt to create a ext2 partition on the micro sd to link to my internal storage directory. I used the Partition Wizard mini tool to create a ext2 partition in windows. Unfortunately after starting up Link2sd and selecting the format of my ext partition (ext2), Link2ds gives me an error telling me that the mount script was unable to be created. I've read that if we get this error, we can select ext4, even if we are using a different partition format. This got rid of the error. Mount script was successfully created. Autolink is selected, which should install new apps directly to the new partition. It doesn't, not for me at least.
I've read several guides around the internet dealing with this issue, as well as completely different methods besides Link2sd, and nothing seems to work for me. My goal in this is to supplement the capacity for apps. I would love to find a way to store all the library, devlik, and app files for each app on the external card, rather than having to keep some of each app on internal, and its larger counterparts on external. As you know, apps are constantly updated, and what seems to happen is if you install an app, then link it to the sd card, and the app gets updated in the future, the updated portion will get installed on the internal card, making your 'linked' app kind of pointless. What I'd really like to do is disregard the phone's internal storage altogether and use something like a 64 gb card as the phones internal storage. This may or may not be possible.
I'm not a programmer. I have a very basic understanding of how these things work. When it comes to things like this, I am literally standing on the shoulders of giants, and benefiting from their tenacity and willingness to share the fruits of their labors. Their exploits, and the internet that tells their story, have allowed me to root and modify practically every console and android device I've ever owned. With that being said, thank you to all that have been involved in unraveling the real potential of this device.
So, do any of you fine saints and scholars know of a way to get around the feeble storage capacity of our aquos crystal?