This is just an idea. I tried it on my Nokia 6.1 (2018) (PL2) running Android 10, and it worked; so I thought it might work on other devices too. My device:
Android 10 Q
System-as-root
A/B slots
Released with Project Treble support (and hence has the fstab in the vendor partition)
DM-verity, force-encryption and disk quota disabled with this mod by Zackptg5.
It basically uses a single partition to store the contents of what I call two different userdata "profiles". Normally, you have one userdata partition on a device, and that stores one profile. Here, however, I used a subdirectory on the root of the userdata partition to store the contents of the second profile, and modified the fstab to correctly bind-mount it on /data. Bind-mounting made things simple in my opinion--I didn't have to go about actually repartitioning my storage. The reason this works is that any changes you make to your phone on the lines of installing and updating apps, downloading files, changing settings, etc. are all reflected only on the userdata partition. No other partition on an android phone is ever touched unless the system is updated. Hence, the userdata partition is the only partition you need to mess around with in order to have two profiles.
===================================DISCLAIMER:
I am NOT sharing a solution. I am only sharing an idea for you to try and/or improvise on. It may work, it may not. I will not hold your hand; you will have to use your own knowledge and common sense. I am not responsible for anything that goes wrong on your device.
If you do not understand what is going on in this post, please do not try this.
There is a reason I'm not explaining all the terms I'm using here. I assume that if you, the reader, want to try this out, you a) have some knowledge and experience, and b) have the fire in your belly to research to learn more about what you don't understand.
===================================
Now for the fun:
The first thing I did was to create a new mountpoint the userdata partition. This I made on what is the root filesystem of the device; on a system-as-root device, it would be on the root of the system partition, and on a non-system-as-root device, it would be on the root of the boot ramdisk. I named it userdata/. Accordingly, I edited my fstab.qcom (at etc/fstab.qcom on the vendor partition for my device) to mount the userdata partition on /userdata/ instead of /data/:
Code:
#<device> <mountpoint> <type> <options>
/dev/block/bootdevice/by-name/userdata /userdata <whatever whatever whatever> <you'd probably have to disable options like fileencryption, quota, check (verification), etc.>
and to mount the second profile's directory. Note that it is bind-mounted:
Code:
/userdata/userdata/ /data none bind
Now to switch between the two profiles, you'd switch between the original fstab and the one you just modified.
That is (most of) it. Some things I noticed:
The device would refuse to boot initially. What worked was to backup and wipe my data, boot, create the second profile's directory and copy the contents of the just-created userdata profile into the second profile's directory. In other words, I couldn't run a "first boot" on the second data profile--I had to copy an existing profile into the second profile. I really don't know why this happens.
I suspect that disk quota, filesystem encryption and verification will mess with this (or rather, the other way around). I can't be sure, because I have all three disabled.
Having a shared Internal Storage (/data/media/0/) is convenient. For this, I just bind-mounted that too:
Code:
/userdata/media/0/ /data/media/0/ none bind
This can also be used to easily achieve dual booting on an A/B device, as long as you don't use seamless updates. One ROM per slot can be installed, and the fstab.qcom on one of the vendor partitions can be configured to use the second profile. This way, there would be no need for an external SD card or additional partitions.
I'm pretty sure there will be other hurdles with other devices and other android versions. As I said, I'm just here to share an IDEA, and NOT a foolproof, one-size-fits-all solution. I hope this helps other people make their lives simpler. Please do share your notes on this thread if you manage to get it working on your device!
Its easy to have two roms on one device and its simple,just take a nandroid aof your current rum,now flash another rom an set it up,when u need the other rom just restore your nandroid and so on,i have 4 roms,all fine,lol.
But that's kinda inefficient, don't you think? If you just swap a single file instead of the whole data partition, it's much faster--it takes as long as rebooting + a few milliseconds.
But well, whatever suits you
Hey bro can u pls explain the second code line u mentioned???
varunrocks17 said:
Hey bro can u pls explain the second code line u mentioned???
Click to expand...
Click to collapse
/userdata/userdata/ /data none bind: (this is the line right?)
This bind-mounts the directory /userdata/userdata on /data. /userdata/userdata (directory /userdata under the userdata partition that we previously mounted) is the directory under which the contents of the alternative userdata partition are stored.
Bind-mounting is a means by which a folder can be treated as a device to mount (as opposed to a normal block device or partition). As the mount(8) documentation states, it is a way to "Remount part of the file hierarchy somewhere else."
By this mechanism, the /userdata/userdata folder is made to look like the entire userdata partition. In other words, when you access anything under /data/, you're in fact accessing /userdata/userdata/.
I did something similar to a Jellybean. That is, quite long time ago. Stock fw didn't support encryption. So I made a hack that used cryptsetup and vold.decrypt triggers. That way only framework had to restart. It probably is not that simple anymore...
Anyways, what I learned that it wasn't worth it, so I didn't release it back then. Back then there was a real space shortage and it wasn't wasted like nowadays....
Thanks for that userdata idea that's what I was messing around and. Creating multiple partitions for each rom ...
Btw one question :
Kernel intially mounts vendor then from vendor/etc/fstab.qcom all others are mounted ..?
Or kernel have the predefined vendor system and userdata partition locations ..??
I am really confused here ..
That's why my multi boot was bit messy..
aryankaran said:
Thanks for that userdata idea that's what I was messing around and. Creating multiple partitions for each rom ...
Click to expand...
Click to collapse
Glad I could help
aryankaran said:
Kernel intially mounts vendor then from vendor/etc/fstab.qcom all others are mounted ..?
Or kernel have the predefined vendor system and userdata partition locations ..??
Click to expand...
Click to collapse
On my system-as-root device treble-enabled device, the vendor partition is mounted by the kernel. There is a node in the kernel's device tree blob (dtb) that specifies the vendor mount. When the kernel is fully initialized, it has its own /dev filesystem, using which it mounts the vendor partition. I hope that part is clear.... not sure if I explained it nicely...
Once the vendor is mounted, /vendor/etc/fstab.qcom is read and all the other partitions are mounted from there.
Ok it means it's just the same scenario as it was till Android 7.1.2 that boot image mounts all partitions..
Just difference that kernel now mounts vendor and further processed by fstab ..
Related
So I was using Slax. Great LiveCD/USB linux, extremely customizable, modular, fast, and small, and has the capability of either:
- saving changes to its rootfs onto an AUFS mounted on a non-linux FS (FAT32, NTFS) using posixovl (POSIX Overlay FS) with metadata (permissions, etc.) being held in files
- saving changes to a fixed-size loop mount image.
This got me thinking.
If we could insert all the necessary modules, code, etc. for posixovl into the Android linux, and make a modified a2sd script that takes advantage of posixovl, we could effectively do away with the requirement for crazy partitioning.
It should be simple enough for ROM devs to implement, assuming it's ready and installed:
1. Create folder on main partition if it doesn't exist, something like /sdcard/system/[app, app-private, dalvik-cache, app_s]
2. In the init scripts, before the a2sd stuff, mount /sdcard/system with posixovl on /system/sd
3. Run a2sd as normal, it should automatically just work.
I'll hopefully test this once I get my phone to a stable development/testing stage, and I don't need to make phone calls for a while. Anyone else is welcome to try to implement this idea.
My current test environment:
- HTC Dream (T-mo G1) with the deadly SPL of doom
- Cyanogen Experimental, latest build
- Amon_RA's modded recovery
- Wipe /data, move all existing apps to backup, remove a2sd partition, Backup for Root Users to restore some settings and data
Anyone with ideas or improvements, please let me know.
To be tested:
- Feasibility (can it work?)
- Functionality (does it work?)
- Portability (Can it work on other ROMs and devices like Hero, Pulse, Blur etc.? If so, will likely be moved to XDA's new Android board)
- Stability (Will everything Force Close on boot? Does it run fast enough? Does anything get corrupted over time?)
Links:
- http://sourceforge.net/projects/posixovl - Sourceforge page for posixovl
In desktop linux you can create a file with the touch command, and mount the file to a mountpoint after formatting it to ext4 for example.
Maybe this is the easier way?
I have done this about 5 years ago, but I will try it today and report if it worked.
edit: ok done already:
1. create a file of the desired size, eg: dd if=/dev/zero of=filename bs=filesize count=1
2. use mke2fs to format the file
3. create a mountpoint and mount the file
thats all. Now I have a 128MB file on my PC, mountable and usable like a partition.
Archont said:
In desktop linux you can create a file with the touch command, and mount the file to a mountpoint after formatting it to ext4 for example.
Maybe this is the easier way?
I have done this about 5 years ago, but I will try it today and report if it worked.
Click to expand...
Click to collapse
As far as I know, you can do that on the mobile Android, too, and that does work in theory. This technique involves mounting a loop filesystem, and it too will allow one-partition apps2sd, but it's less flexible, and I would think slower, than the overlay method.
For a 512MB apps image:
Create empty 512MB file
# dd if=/dev/zero of=/sdcard/apps.img bs=1024k count=512
Format it to Ext2
# mke2fs -L Apps2SD /sdcard/apps.img
Unmount existing a2sd
# umount /system/sd
mount new a2sd image
# mount -t ext2 -o loop /sdcard/apps.img /system/sd
Make the usual directories, and a mountpoint for the old a2sd partition
# mkdir /system/sd/app; mkdir /system/sd/app-private; mkdir /system/sd/dalvik-cache; mkdir /system/sd/apps-tmp
Mount the old a2sd partition
# mount -t ext2 /dev/mmcblk0p2 /system/sd/apps-tmp/
Move all files from the old partition to the image file
# mv /system/sd/apps-tmp/* /system/sd/
Unmount and remove the mountpoint, we don't need it anymore
# umount /system/sd/apps-tmp
# rmdir /system/sd/apps-tmp
Finally, you add the following line to the init script where the a2sd auto mount happens, and comment out the old line.
Code:
[...]
mount -t ext2 -o loop /sdcard/apps.img /system/sd
#mount -t ext2 /dev/mmcblk0p2 /system/sd/
[...]
This should do what you described, in theory. I can't say whether it will work or not. I can't tell whether it will or won't screw up your phone, I can't be held responsible if you screw something up or overlook the details. Either of us might have made a typo somewhere; apply common sense before doing anything.
This sounds great! I think this would also be usefull for someone like me, who has a sd card that doesn't want to be partitioned anymore (cross-linked files??). Only thing possible is fat32 or ntfs.
Am I correct with my assumption?
This sounds a lot harder and more complicated then partioning. Your also talking about a lot of work needing to be done just so people can avoid doing a simple thing like partioning a sd card. I would say it would be very difficult alone to get the os to run a virtual mounting service especially since that will take up resources and slow down the phone. There is a reason they only use this technique on live cds is it works but its slow. most of the computers they are running on have 1gig of ram and 2ghz cpu's. i really dont think the g1 can push this.
I do not think that this is great, it definitely is slower than a ext4 partition on a good class 6 microSD card. And it is more vulnerable to data loss since 2 different filesystems including a 20 year old non-journaling fs at the base of this construct are involved.
Another problem that came to my mind: when you mount your SD card as external USB device to a PC, the file containing your apps will no longer be accessible, or Android will make using the phone as external data storage impossible.
Interesting.
There is, however, a major problem: What happens when you unmount the fat partition on the phone in order to connect with a computer using UMS? Answer: everything on the phone will crash and burn since the apps filesystem will suddenly disappear = BAD.
posixovl is a nice find though...
Note that aufs, loopmount linux filesystems, etc., wouldn't be needed with this since posixovl appears to be vfat with posix extensions, so you should be able to just use posixovl directly on the sdcard.
There are several problems with that though... i.e. how reliable is posixovl regarding users tampering with it?
In any case, a prerequisite for use of it would be certain other changes being planned...
You might want to contribute to this thread:
http://forum.xda-developers.com/showthread.php?t=577941
(note: the thread links to a thread at android-platform, the one here has, as expected, gone off on a tangent... just ignore the junk.)
TylTru said:
So I was using Slax. Great LiveCD/USB linux, extremely customizable, modular, fast, and small, and has the capability of either:
- saving changes to its rootfs onto an AUFS mounted on a non-linux FS (FAT32, NTFS) using posixovl (POSIX Overlay FS) with metadata (permissions, etc.) being held in files
- saving changes to a fixed-size loop mount image.
This got me thinking.
If we could insert all the necessary modules, code, etc. for posixovl into the Android linux, and make a modified a2sd script that takes advantage of posixovl, we could effectively do away with the requirement for crazy partitioning.
It should be simple enough for ROM devs to implement, assuming it's ready and installed:
1. Create folder on main partition if it doesn't exist, something like /sdcard/system/[app, app-private, dalvik-cache, app_s]
2. In the init scripts, before the a2sd stuff, mount /sdcard/system with posixovl on /system/sd
3. Run a2sd as normal, it should automatically just work.
I'll hopefully test this once I get my phone to a stable development/testing stage, and I don't need to make phone calls for a while. Anyone else is welcome to try to implement this idea.
My current test environment:
- HTC Dream (T-mo G1) with the deadly SPL of doom
- Cyanogen Experimental, latest build
- Amon_RA's modded recovery
- Wipe /data, move all existing apps to backup, remove a2sd partition, Backup for Root Users to restore some settings and data
Anyone with ideas or improvements, please let me know.
To be tested:
- Feasibility (can it work?)
- Functionality (does it work?)
- Portability (Can it work on other ROMs and devices like Hero, Pulse, Blur etc.? If so, will likely be moved to XDA's new Android board)
- Stability (Will everything Force Close on boot? Does it run fast enough? Does anything get corrupted over time?)
Links:
- http://sourceforge.net/projects/posixovl - Sourceforge page for posixovl
Click to expand...
Click to collapse
lbcoder said:
Interesting.
There is, however, a major problem: What happens when you unmount the fat partition on the phone in order to connect with a computer using UMS? Answer: everything on the phone will crash and burn since the apps filesystem will suddenly disappear = BAD.
Click to expand...
Click to collapse
I kinda overlooked that point. Oops.
Though this same problem does exist on regular apps2sd when you remove the card without dismounting it, killing all apps and their processes, and freezing Dalvik's method of autostarting some apps.
I do tend to swap cards every now and then, but only after a reboot. Dalvik re-enumerates and caches dex, which makes for a slow boot, but it seems to just work in most cases that the apk install doesn't drop the app's functional payload (helper Linux/shell utils, libraries, NDK .so's) in /data/data (like some emulators, the Android Scripting Environment)
lbcoder said:
There are several problems with that though... i.e. how reliable is posixovl regarding users tampering with it?
Click to expand...
Click to collapse
As far as I know, the metadata files are marked as hidden and system files, and begin with a '.'. And I haven't tried this, but I think modifying the actual files under Windows has no negative effects, but moving, deleting, or copying files would likely be a no-no.
Also, I don't think there's a 'fsck' for posixovl, meaning that if any metadata files were screwed with the wrong way, the entire overlay FS would be trashed.
lbcoder said:
In any case, a prerequisite for use of it would be certain other changes being planned...
You might want to contribute to this thread:
http://forum.xda-developers.com/showthread.php?t=577941
(note: the thread links to a thread at android-platform, the one here has, as expected, gone off on a tangent... just ignore the junk.)
Click to expand...
Click to collapse
I checked that out. It was actually a small inspiration for what I was thinking of.
In any case, Android's package management system needs an overhaul. The package storage needs to be de-Linuxified, as all it is is a bunch of .apk files and .dex/.odex files, the UIDs of apps are in the AndroidManifest.xml, right?
In a somewhat unrelated note, app data needs to be moved to a specified folder structure on the sdcard. My card is full of folders in the root directory with random names.
If I'm understanding you correctly, you're talking about storing an image file on the normal SD card partition(which has to be FAT32 as far as I've seen) and then mounting it, correct? This idea has been talked about at length before on at least 3 separate occasions(2 of which were on this very forum) and found to be a bad idea due primarily to massive security risks since FAT32 has no permissions.
Also, I believe cyanogen ended up dumping unionfs/aufs due to rampant memory issues.
If you are talking about mounting an image from the FAT32 partition, please don't endorse this. We don't want to be throwing in security bugs into android, especially ones such as this which can't be plugged up.
As a modification to what I said: If you're suggesting doing this(or something similar) on a separate filesystem, after that project to change the AOSP to support one with permissions is finished, then I'm in full support.
If you want to go for a single partition on the sd card, why don't you just make the entire card use ext4? Your linux desktop reads it anyway, it uses journaling and so on, I guess it would be faster compared to fat32 and it is definitely safer to use.
And i guess it is not too complicated to mount this partition and use it for pictures, music and so on.
I have not tried this (yet) and I go to bed in 20 minutes, but maybe I will start testing something in that direction tomorrow.
[email protected] said:
If I'm understanding you correctly, you're talking about storing an image file on the normal SD card partition(which has to be FAT32 as far as I've seen) and then mounting it, correct? This idea has been talked about at length before on at least 3 separate occasions(2 of which were on this very forum) and found to be a bad idea due primarily to massive security risks since FAT32 has no permissions.
Also, I believe cyanogen ended up dumping unionfs/aufs due to rampant memory issues.
If you are talking about mounting an image from the FAT32 partition, please don't endorse this. We don't want to be throwing in security bugs into android, especially ones such as this which can't be plugged up.
As a modification to what I said: If you're suggesting doing this(or something similar) on a separate filesystem, after that project to change the AOSP to support one with permissions is finished, then I'm in full support.
Click to expand...
Click to collapse
UNIX permissions don't do anything in the way of "security" unless you have no access to the actual storage device from another computer (as is the case with the unrooted Dream's internal memory), or unless encryption is used. The posixovl driver OVERLAYS Unix permissions over Fat32 filesystems. But even still, with Unix permissions, nothing's stopping someone else from mounting the Ext2 partition and using chown and chmod.
And the image file on the SD card's Fat32 partition is a complete Ext2 partition complete with Permissions. Nothing is lost.
Archont said:
If you want to go for a single partition on the sd card, why don't you just make the entire card use ext4? Your linux desktop reads it anyway, it uses journaling and so on, I guess it would be faster compared to fat32 and it is definitely safer to use.
And i guess it is not too complicated to mount this partition and use it for pictures, music and so on.
I have not tried this (yet) and I go to bed in 20 minutes, but maybe I will start testing something in that direction tomorrow.
Click to expand...
Click to collapse
We'd just have to find the part in the Android that mounts /sdcard/, and change 'vfat' to 'ext2'. The only reason I wouldn't do this, is because it would immediately make it incompatible with Windows and Mac's default FS drivers. As far as I know, the only FS's that are supported universally within Linux, Mac, and Windows, are FAT and NTFS. And NTFS can be made to have crude support for permissions through security descriptors. Although, the Dream SPL, the Recovery images, and most of Android only uses FAT32.
This is discussed in android-platform Group :
http://groups.google.com/group/andr...read/thread/bf0709c157451cd9/f6aee1830c84620f
The goal is to be able to integrate this in android.
And not having to partition the SDCard is one of the requirements so far...
Unix permissions are not stored using fat or vfat, and ntfs is not really supported in desktop linux and i guess it cannot be used in android linux.
I would not use windows anyway so this is no problem to me, and there are drivers around to mount ext systems in windows. As Mac OS is based on unix there will be a solution for this too.
Access usind adb push and pull, via ftp and so on is not touched by using ext4 on the entire sd card I guess.
And if you don't go the easy way using gparted on a live cd or usb device to create 2 partitions, you will have to live with some disadvantages anyway.
Finally I want to say that my ideas are far from being perfect or usable at all, I see this thread as a kind of brainstorming.
im not as linux or android savvy as probably any of you but before the current method of creating a swap partition became the "standard", people used a swap file on the sdcard and linked that. seems similar to what you are suggesting here.
ofcourse when mounting the fat partition elsewhere (ums in windows for example) that swap file could no longer be used within android. i dont see a way to get passed the same issue, but worse here, due to android not having crucial apps when the fat partition is mounted.
then again, i am pretty much over my head in this conversation and could be over looking something...
I'm kind of fascinated by the FUSE + posixovl method of doing this. In the long run I have a feeling that it's going to perform like ****, but I think it's worth testing.
I managed to get both libfuse and mount.posixovl built and running on Android.
posix-overlay(/sdcard/fuse) on /sdcard/fuse type fuse.posixovl (rw,nosuid,user_id=0,group_id=0,default_permissions)
Giving this a little testing now, it definitely works.
Code:
/sdcard/fuse # ls -l
drwxr-xr-x 2 1000 1000 4096 Nov 5 17:17 test
TylTru said:
UNIX permissions don't do anything in the way of "security" unless you have no access to the actual storage device from another computer (as is the case with the unrooted Dream's internal memory), or unless encryption is used. The posixovl driver OVERLAYS Unix permissions over Fat32 filesystems. But even still, with Unix permissions, nothing's stopping someone else from mounting the Ext2 partition and using chown and chmod.
And the image file on the SD card's Fat32 partition is a complete Ext2 partition complete with Permissions. Nothing is lost.
We'd just have to find the part in the Android that mounts /sdcard/, and change 'vfat' to 'ext2'. The only reason I wouldn't do this, is because it would immediately make it incompatible with Windows and Mac's default FS drivers. As far as I know, the only FS's that are supported universally within Linux, Mac, and Windows, are FAT and NTFS. And NTFS can be made to have crude support for permissions through security descriptors. Although, the Dream SPL, the Recovery images, and most of Android only uses FAT32.
Click to expand...
Click to collapse
Ya, I meant more from the standpoint of a rogue app. Since FAT32 has no permissions, what would prevent such an app from modifying the stored image file to, say, change a trusted app with superuser permissions to some new code of its own making to, for example, watch for credit card numbers and send them back to the person who made the original rogue app? I'm always hesitant with any ideas that suggest storing an image file on the sdcard for appstosd for this reason.
Forget it, it's useless.
An overlay filesystem prevents you from enabling USB storage.
If you want to play around with FUSE on Android, here's a repository for my port of libfuse..
http://github.com/cyanogen/android_external_fuse
Hi,
I have an idea. I used symbian S60 of Nokia, Symbian can install app to sdcard. I see that when I mount sdcard to PC, my phone immediately hold all activations of all applications on my phone. And they have a PC sync software that help us access sdcard but not mount sdcard (like that we copy file from computer to sdcard via debug mode on android).
I think we should find out how symbian can do it and we will use their way .
I'm not a developer, I'm just an user.
I talked to a few people about this, and some deep kernel voodoo is going to be needed for this to really happen without partitioning.
Another idea is to forge ahead with this, and ditch the "unmount fs for usb storage" and use RNDIS + Samba or something like that instead to access files on SD. I kind of like this idea.
Hi,
This has been asked many times before with no real solution that applies to different devices.
I'm running out of space on my /system partition and can't install any more apps even though I don't have that many installed.
I want a way to re-size the Android partitions manually to whatever size I want. Or just delete all current partitions and create new ones.
How do I do that? Is there any GUI partitioning tools similar to the ones available for Windows?
I don't want to move files from /system to another partition. I want to change the partition size.
My current /system partition:
For what reason are you moving apps to /system? You can't install them there, you have to push/move them there, installs go to /data. So keep them in /data, where they're installed by default. You have tons of space available there.
Partition table (start addresses and sizes) is hard-coded in bootloader, and can be redefined in kernel boot parameters (in this case recovery needs to be recompiled with the same parameters too, otherwise it won't write to the same partitions the kernel will read from). You're welcome to hack any of those. As you could probably understand from this paragraph, I wouldn't expect having GUI tools for that.
Thanks for the reply.
I'm not trying to move apps to /system. I thought apps are installed there by default because every time I try to install a new app it gives me an error message saying that there is not enough space on /system.
Now I know that apps are not installed in /system.
I just need more space in /system so I can install new apps without any errors.
What can I do to get more space on /system partition? Can I replace the bootloader?
I don't have any Android programming experience. I probably need something that is available out there to do the job.
In stock form, you shouldn't even have write permissions to /system. Nothing should be ever written there, and it can be 99.99999% utilized - there shouldn't be any free space left for anything, it shouldn't normally be used.
If you're getting that error when trying to install an app - you need to check what's reporting the error. It's not a "real" error, it means there's something wrong with your phone.
Try wiping cache partition from recovery...does this make any difference?
Jack is correct.
Swyped from my DesireS
refer to this
if this may help you http://forum.xda-developers.com/showthread.php?t=1959691
:highfive:
mayank88288 said:
refer to this
if this may help you http://forum.xda-developers.com/showthread.php?t=1959691
:highfive:
Click to expand...
Click to collapse
Way to bump a year old thread :thumbup:
“I'm bad and I'm going to hell, and I don't care. I'd rather be in hell than anywhere where you are. ”*―*William Faulkner
Let me start with: I know that there have been many posts on this, but before you get mad, I was unable to find an answer to what I specifically want to do.
For reference: I am a software developer and sysadmin with a decent amount of Linux experience, but not a lot of android specific experience.
Now that the introduction is out of the way:
What I would like to do is completely remove the "USERDATA" partition (the "Internal SD card"), grow the "SYSTEM" partition to fill that space, and then mount my SD Card (external) as the SD Card that the system sees.
I'm currently on Cyanogenmod 10.1 but want to upgrade to 11 soon.
The reason I want to do this is because:
I have all if my apps that I can set to install to SD Card
Both "internal" partitions are full (only about 200MB is available for pictures/etc. and I can no longer update apps)
Camera (and pretty much everything else as well) stores to the Internal SD card by default
If the system partition was 1.1+1.4=2.5GB and all of my apps were "installed" to a real SD card, it would be a lot more comfortable.
So, here's what I am thinking *might* work (maybe not in the right order, though?):
Point the fstab entry for the internal SD card to the external SD card
I have the PIT file. I will delete the "USERDATA " and grow "SYSTEM" to fill the space
When I write it out in steps, it seems pretty simple...
My concerns:
Will a ROM update (to CM11) re-partition back to the old way (and, in the process, break a bunch of stuff)?
I don't ever plan to go back to stock android or change to another ROM (other than upgrades).
Thanks for reading this long post and for any insight you may be able to provide.
--mobrien118
It's a wonderful idea if it works.
Sent from my SAMSUNG-SGH-T769 using xda app-developers app
Modifying partitions is a bit dangerous.
But I have to ask you why do you need another GB of /system storage?
There was a line you can put in the build.prop that flips your ext. SD with the internal one on cm10 I believe.
This'd interest me if I could get rid of usbdisk and sdcard0 merged.
It would need the phone to be repartitioned though, causing issues with the backups and ROMs.
You may even have to compile cm from source.
Its a lot of trouble
Sent from my SAMSUNG-SGH-T769 using Tapatalk
I just did so on S4 Mini with cm-11 Android 4.4.
First I was thinking of using symlinks and/or bind mounts to redirect to the the external sdcard, but that's a bit of a hassle because
1) Since 4.2: both emulated and external storage is mounted with a fuse layer on top not supporting symlinks
2) Since 4.4: no more global write access on external storage
So moving data was the simplest solution. Besides providing (much) more space my sdcard is also around 20% faster in sequential writes: 8.5 MB/s internal vs 10.5 MB/s external. Is it really 2014?
I haven't yet decided what to do with the original data partition, so for the moment I left it unused. Hence I haven't touched the internal partition table.
Quick summary
partition sdcard (gdisk)
I recommend using GPT, this lets you work with partition names rather than numbers. For the sake of still having an "official" external sdcard I made two partitions. Keep in mind that it's usually the first partition which gets automatically mounted as external sdcard. So I made the 2nd partition the new home for data. This partition however has to be manually specified in the ramdisks fstab which involves flashing the boot partition.
format the new partitions (mkfs.ext4)
copy the original /data directory tree to the new data partition
extract initrd from boot.img (abootimg)
extract files from initrd (gunzip & cpio)
replace the /data entry in fstab pointing at your new data partition
re-pack initrd and boot.img (gzip, cpio & abootimg)
flash boot.img onto the boot partition (dd)
If you use recovery, you also have to edit it's fstab (analog to boot.img mentioned above)
done
Alternatively has anyone tried an init.d script? I see those scripts get executed before the mounting of data & sdcard
Meanwhile the original userdata partition got replaced by 3 new partitions: system2, cache2 & userdata2 which are now used for a dual boot ROM.
I've only changed GPT, not PIT. ROMs and Recovery don't use PIT, so as long as Heimdall/Odin isn't involved it should not cause any issues.
Hey guys,
So after read all that, I am also vry interested in what the OP has suggested. I get that the pit doesn't need to be affected, but as the OP asked, when flashing a new rom or updating an existing, would the partition be reformatted back to the way android handles it, ie; back to the system and data seperate and the sdcard not being used as the internal partition?
I am no developer and only have minimal knowledge in linux and android programing, but I am a quick study and any guide to help me sort this would be greatly appreciated.
Also I am about to get a second S4 mini specifcally for doing things like this so if I brick I don't care?
My next question is could it be possible to code the PIT file to do this for you so that you can just flash that through odin, but again would flashing roms affect this.
Cheers,
Sora.
aguaz said:
I just did so on S4 Mini with cm-11 Android 4.4.
First I was thinking of using symlinks and/or bind mounts to redirect to the the external sdcard, but that's a bit of a hassle because
1) Since 4.2: both emulated and external storage is mounted with a fuse layer on top not supporting symlinks
2) Since 4.4: no more global write access on external storage
So moving data was the simplest solution. Besides providing (much) more space my sdcard is also around 20% faster in sequential writes: 8.5 MB/s internal vs 10.5 MB/s external. Is it really 2014?
I haven't yet decided what to do with the original data partition, so for the moment I left it unused. Hence I haven't touched the internal partition table.
Quick summary
partition sdcard (gdisk)
I recommend using GPT, this lets you work with partition names rather than numbers. For the sake of still having an "official" external sdcard I made two partitions. Keep in mind that it's usually the first partition which gets automatically mounted as external sdcard. So I made the 2nd partition the new home for data. This partition however has to be manually specified in the ramdisks fstab which involves flashing the boot partition.
format the new partitions (mkfs.ext4)
copy the original /data directory tree to the new data partition
extract initrd from boot.img (abootimg)
extract files from initrd (gunzip & cpio)
replace the /data entry in fstab pointing at your new data partition
re-pack initrd and boot.img (gzip, cpio & abootimg)
flash boot.img onto the boot partition (dd)
If you use recovery, you also have to edit it's fstab (analog to boot.img mentioned above)
done
Alternatively has anyone tried an init.d script? I see those scripts get executed before the mounting of data & sdcard
Click to expand...
Click to collapse
I just managed to replace my internal sd with the external sd following your ruff guide. thank you very much! At first I struggled a bit getting it to work, because I had encrypted my data partition before -.- this seems to change something in the fstab / mounting / boot-up process, I couldn't get my S4 mini to boot with just changing the fstab.qcom in boot.img. With my recovery (TWRP) it worked from the start editing recovery.img's fstab.twrp /data mount point.
After decrypting(formatting) /data and re-editing fstab.qcom in boot.img it finally works I'm so happy! Enjoying a lot of space on my sdcard now!
usefull threads / information I learnt from:
Partition structure of S4 Mini
Encryption of ExtSD & some fstab information
Editing initrd
abootimg ReadMe
(Links last tried 28.05.2015)
What way are partitions made in this phone? Are they described into in fstab-like files or hardcoded in recoveries/kernels?
It will be nice to make revision of mapping for reasons:
1. Too much space for /system. I have more than 900mb free with CM11.
2. Possibility to unite /data and /sdcard binded partitions, like it's made on many newer devices. Oops, seems like already done in at least CM.
3. Adding unused space to /data and /cache(ex. for ART).
Is it possible, if yes - why it is not used?
It is not possible to resize the partitions (I tried that on my own, without success).
We are able to use/modify fstab to switch partitions (e.g. userdata and cache) but it is recommended to do this in the kernel because then the recovery will use the new layout also.
The last method is new for me, I don't know how to do this.
fstab.qcom is in root (in cm11).
Tried? Please post links/method ^_^
Sorry, I was not at home, so providing links was too hard to try.
Here is my post -> http://forum.xda-developers.com/pho...0-photon-q-t2838299/post58401143#post58401143
Read also the post after that one.
Hiya! I don't believe my problem is device specific. The background of how I ended up in this crappy situation is, but I believe the resulting issue is general. Should I be wrong, tell me and I'll move this to my device's section.
Short question: how can I (and can I?) restore data in a partition that got deleted, if no new filesystem has been created over it?
Long background: I have a Xiaomi Mi2-S 32GB. It used to have a peculiar layout: a double system partition (/system1 and /system2)¹, a small internal storage (/userdata)², and a big emulated SD card (/storage)³.
Let's explain why:
¹ False dual boot: the active system is installed in the first partition. When installing an update with the official app, the newer system gets installed in the second and that one gets booted. So, should this newer system fail to boot, you have an older one correctly working and ready to boot.
² and ³: so that the whole storage partition containing photos, music, videos, downloads, backups, saved games and such can be accessed with MTP, while the userdata containing apps and complementary system things is kept safe. This last decision, however, brings up a new problem: userdata can't be accessed by user to put his files or by apps without root permissions to store data (like photos), while storage can't be used to install apps, or even to move them using Link2SD or such. Some users might find storage is insufficient for their videos and music, while others might find userdata is too little for their games, and they are both stuck in this situation.
I was in the second group, so I altered my layout using stillka's guide on xiaomi.eu (Sorry, I can't post links). I extended my userdata, so that my storage resulted smaller. Plus, I understood altering a partition would mean deleting all the partitions before that one, and recreating them thereafter.
Until this point, all was OK. I installed Ivan's AOSP Lollipop for unmerged partitions, and found out it would experience random reboots with True Dual Boot. So I stuck with False one and forgot about everything. I kept that version without updating for a long time.
Then, several months later, my phone started rebooting randomly anyway. I figured I would come back to MIUI to get Xiaomi's support for an official ROM.
Little did I know they decided to change layout in the meantime. MIUI got so big the size of the two systems was insufficient. So they decided to merge them into an unique partition big enough. So, while flashing with the official tool MiFlash, it practically altered my system layout, having to delete all that was placed before them (cache, userdata and storage), never telling me what it was going to do, advising me to back my storage up somewhere. All I did was back up my userdata into storage, confident flashing their official ROM with their official tool would just write into system, since nobody told me otherwise.
So this is the result: the old, small size of userdata is back, and everything that comes after is left without any filesystem: these are the last line in parted's print output
20 327MB 336MB 8389kB ext4 persist
21 336MB 1409MB 1074MB ext4 system
22 1409MB 1812MB 403MB ext4 cache
23 1812MB 5570MB 3758MB ext4 userdata
24 5570MB 31.3GB 25.7GB storage
Click to expand...
Click to collapse
I've tried parted's rescue command, but it is unable to find a partition lying there. I don't have my old layout, so I'm not able to precisely know where my old storage began, but I remember it to be around 18 GiB in size. I've tried all ranges possible (from the current end of userdata, 18 G from the end and so on) but no dice.
Can someone tell me if there is any hope, and what can I try?
Now I'm trying to dd the whole eMMC, or even just the last partition, to my computer to work on it using, say, testdisk. There is just one problem.
Obviously, I must issue the commands in my PC's environment, as I've nowhere to dump the biggest partition in my phone to, on it. So it goes something like
Code:
adb shell su -c "cat /dev/block/mmcblk0" | pv > mmcblk0.raw
The problem is, even if my phone was rooted by TWRP and in my options menu, the su binary is not found
/sbin/sh: su: not found
Click to expand...
Click to collapse
What should I do? Should I manually push the su binary in /system/bin? Where should I take su? From my PC?
This link should be helpful to you. Though its for MI3, the guy explains exactly how he recreates all the stock partitions one by one using the parted utility.
However, I think even before you try that, I think you should consider using the shortcut suggested in this link. If you can alter the flash_all.bat slightly and add the gpt_both0.bin, it can re-create the stock partitions (at least this is what the poster has done for Mi3/Mi4, since yours is Mi2, I'm not so sure, you may have to find out).
Finally, here is one more link that you may want to read up.
---------- Post added at 06:34 AM ---------- Previous post was at 06:34 AM ----------
This link should be helpful to you. Though its for MI3, the guy explains exactly how he recreates all the stock partitions one by one using the parted utility.
However, I think even before you try that, I think you should consider using the shortcut suggested in this link. If you can alter the flash_all.bat slightly and add the gpt_both0.bin, it can re-create the stock partitions (at least this is what the poster has done for Mi3/Mi4, since yours is Mi2, I'm not so sure, you may have to find out).
Finally, here is one more link that you may want to read up.
The problem is I don't have to restore stock partitions. That was already done against my knowledge, only that the last partition was left without a filesystem. If anything, I should restore my previous, custom layout, I have no trace left about.
I've managed to use testdisk. It is not able to find any partition in my phone eMMC though...
Testdisk's failure might be because of a wrong geometry setting, even if it sounds strange to me.
This is the ouput of parted's print
parted print said:
Error: Both the primary and backup GPT tables are corrupt. Try making a fresh
table, and using Parted's rescue feature to recover partitions.
Model: (file)
Disk /media/Storage/mmcblk0.raw: 31.4GB
Sector size (logical/physical): 512B/512B
Partition Table: unknown
Disk Flags:
Click to expand...
Click to collapse
This is fdisk's p
fdisk p said:
Disk mmcblk0.raw: 29.2 GiB, 31354139648 bytes, 61238554 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00000000
Device Boot Start End Sectors Size Id Type
mmcblk0.raw1 1 4294967295 4294967295 2T ee GPT
Click to expand...
Click to collapse
2T? Seriously?
Given that parted doesn't give those errors when run directly in adb, maybe something has gone wrong in the process of dumping my memory. I've issued this command:
Code:
adb shell dd if=/dev/block/mmcblk0 | pv | dd of=/media/Storage/mmcblk0.raw
Did I do something wrong?
This is what testdisk tells me in the analyse menu:
testdisk analyse said:
Disk mmcblk0.raw - 31 GB / 29 GiB - CHS 3812 255 63
Current partition structure:
Partition Start End Size in sectors
1 P EFI GPT 0 0 2 267349 89 4 4294967295
Warning: Bad ending head (CHS and LBA don't match)
No partition is bootable
Click to expand...
Click to collapse
It also detects an Intel table, which is rather odd. Selecting Intel or GPT gives the same result anyway, a big, round zero.
Rather than messing with partition tables using parted, I think there is a simple thing you can try:
1. Restore stock partition tables as it is (using the linked guide or some other means).
2. Restore the stock partitions themselves, something like this:
dd if=/sdcard/system.img of=/dev/block/mmcblk0
dd if=/sdcard/boot.img of=/dev/block/mmcblk1
These are just examples, you know which partition number corresponds to system.img, boot.img, etc. If you can do the above successfully, you will have restored the handset back to stock settings (both partitions and data) and it should start working in theory.
I'm not sure whether I'm not describing my problem clearly or I'm not understanding your suggestion.
The fact is my phone works correctly, it is not bricked. Right now I'm booting MIUI 8. My system partition is alright. My problem is my storage partition (the emulated SD card with all my personal data in it) got deleted, and I'm trying to get it back.
And the layout I had when my storage partition was available was not the stock one, but was already altered by me, as in storage was smaller in order to make more room for userdata (more apps). So, restoring stock layout would not give me my storage's previous start and end points.
k, now I understand your issue! If you want to recover data from a damaged (in this case non-existent) storage partition, have you tried any linux recovery programs (those may be your only option) though I'm not sure how many of them are designed to work with an eMMC.
Or is it the case that you don't care anything about recovering your personal data and just want to fix the storage partition, so the Mi2 file-manager recognizes it?
>> 2T? Seriously?
Yes, that's normal. I've observed even on MediaTek based devices that the partition tables leave that much extra space on the /storage partition (which is typically the last) though its actual physical size is just 2-3GB. You either got the starting/ending points of /storage partition in your MBR/GPT tables wrong (CHS/LBA numbers) or it is just a case of formatting this partition so that the Mi2 recognizes it. In that case, you can just try formatting it to FAT32 or something (but remember that you will loose all your personal data in that case).
Indeed my whole concern is trying to recover what was on it. For all I know, there's the possibility everything was wiped the instant MiFlash destroyed my storage partition, but since no new filesystem was written on it I'm not abandoning hope.
What I did was dump my eMMC to work on it using Linux restore programs (testdisk, mainly), but something must have gone wrong when dumping it. I will try to save the correct partition table and feeding it to TestDisk, but somehow I get the idea this won't solve my problem.
Is there anyway to get the eMMC's geometry parameters to input them manually in TestDisk?
The card is described by parted as "MMC SEM32G", and the parameters I can change are cylinder geometry (number of cylinders, default 3812), head geometry (number of heads: 1-255, default 255), sector geometry (numbers of sectors per track: 1-63, default 63) and sector size.
> What should I do? Should I manually push the su binary in /system/bin? Where should I take su? From my PC?
If you were still unable to take the dump for want of the su binary, then here is an easier way to disk dump the partitions without requiring the su binary at all, but you'll need the CWM image of your Mi2 device:
1. Start phone in Fastboot mode by long-pressing DnVolume+Start buttons.
2. Connect to USB Cable (ensure adb drivers and fastboot are installed).
3. Run this command: fastboot boot /path/to/CWM.img
4. Once phone boots into CWM, adb commands will work! Just mount the system partition in RW.
5. Using adb shell take the dump (you won't be needing root now since the partitions are in RW mode):
dd if=/dev/block/mmcWhatEver of=/sdcard/whatEver.img
EDIT
And if for some reason this doesn't work and you absolutely MUST copy the su binary, you can get the latest zip from the ChainFire.eu site, unzip the su binary and SuperSu.apk files and push the former in /system/xbin/su and the latter in /system/app folders using adb.
Of course, you'll have to provide correct permissions to the su binary, enable the setuid bit on it and finally symlink it to /bin/su.
I got the su binary by letting CWM recovery root my device. However, issuing commands with su copies just the first few bytes. In particular:
Code:
adb shell /system/xbin/su -c "dd if=/dev/block/mmcblk0" | pv | dd of=/media/Storage/mmcblk0.raw
Get 38B, while
Code:
adb shell su -c "cat /dev/block/mmcblk0" | pv > /media/Storage/mmcblk0.raw
Gets 25B.
Anyway, I can't use your suggestion: I don't have an /sdcard partition on my phone anymore: it's the one I'm trying to recover (the last 25.7GB without any filesystem in the partition table I posted in the OP). I must dump them on my PC.