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using the internal memory as a virtual sdcard

I managed to break my micro sd card in half today and I wasn't able to pickup a class 10 or 6 replacement locally so I thought I could use some of the 6gb of internal memory as a virtual filesystem to get me out of trouble.
So, after quickly looking at the android docs and the supported busybox commands I created a 2gb sdcard.img in /data and mounted to /sdcard. I copied some files to it with astro filemanager and fired up raging thunder 2 and it went ahead and downloaded the game data to /sdcard/ and worked correctly.
But, a few apps won't recognise it as an sdcard (Motorola SD card and phone storage settings applet) as well as things like PlayPro (states I have no sdcard present). I thought perhaps I could modify the /etc/vold.fstab file to auto mount the sdcard.img I created using vi but I'm a bit clueless as to what I should change on the dev_mount /sdcard line to get it automounted at boot and hopefully fool the rest of the apps into thinking it is a physical sdcard.
Can anyone possibly point me in the right direction? Not sure how to invoke cmd mode in vi using the milestone qwerty either but I'll keep digging.
What I did (roughly), maybe I'm going about it wrong but any advice would be appreciated.
1. rooted device
2. installed the free terminal app from the market
3. fired up the terminal shell
4. su
5. dd if/dev/zero of=/data/sdcard.img bs=1024 count=1 seek=2000000
6. busybox mkfs.vfat /data/sdcard.img (didn't seem to support -F 32)
7. busybox mount -o loop /data/sdcard.img /sdcard/

+ 1 for this, it would be great to can use internal storage for user data

Why do you let this nice post die.. so "flibbulator" found anything more out?.. I'd like to know more.. like if you got it to work with Music Players and Video players??

Try to mount /data/sdcard.img to /mnt/sdcard (/sdcard is a link to /mnt/sdcard)
or try "export EXTERNAL_STORAGE /sdcard"
I made in a different way: created a 4GB storage.img in /data and mounted it in /sdcard/storage, so internal storage is finally usable for user data
the problem was to set mount point on boot, I can't find a way to execute a script on boot (you can't permanently modify init.rc)

flibbulator said:
What I did (roughly), maybe I'm going about it wrong but any advice would be appreciated.
1. rooted device
2. installed the free terminal app from the market
3. fired up the terminal shell
4. su
5. dd if/dev/zero of=/data/sdcard.img bs=1024 count=1 seek=2000000
6. busybox mkfs.vfat /data/sdcard.img (didn't seem to support -F 32)
7. busybox mount -o loop /data/sdcard.img /sdcard/
Click to expand...
Click to collapse
I have actually tried this on my Droid2Global, and I get the error "unknown operand if/dev/zero" I feel like I am missing the point or do not fully understanding how to use the "dd" command?

the correct syntax is:
dd if=/dev/zero of=/data/sdcard.img bs=1024 count=4194340
4194340 --> 4GB

patton82 said:
the correct syntax is:
dd if=/dev/zero of=/data/sdcard.img bs=1024 count=4194340
4194340 --> 4GB
Click to expand...
Click to collapse
Thank you bro.
Quick question I keep getting these errors. I do have a folder in "/" named "sdcard-int"
Better Terminal Emulator Pro
/ # busybox mount -o loop /data/sdcard.img /sdcard-int/
mount: can't setup loop device: No such file or directory
/ # busybox mount -o /data/sdcard.img /sdcard-int
mount: can't read /etc/fstab: No such file or directory
/ #
Sent from my DROID2 GLOBAL using Tapatalk

you can't place anything in root folder, /sdcard is a link to /mnt/sdcard and is created by init.rc (you can't edit init.rc, it's provided by boot.img, so need to extract from boot.img and repack)
I made in this way but I have to manually execute a script or a command from terminal after every boot to mount storage.img
mkdir /sdcard/storage
su
dd if=/dev/zero of=/data/storage.img bs=1024 count=4194340
busybox mkfs.vfat /data.storage.img
mount -o loop -t vfat /data/storage.img /sdcard/storage

Will be lost anything after reboot when use this storage?
Sent from my MotoA953 using XDA App

all the stuff in img file will not be lost, as long as you put it in /data/
on the contrary the mount point must be restored after reboot

patton82 said:
you can't place anything in root folder, /sdcard is a link to /mnt/sdcard and is created by init.rc (you can't edit init.rc, it's provided by boot.img, so need to extract from boot.img and repack)
I made in this way but I have to manually execute a script or a command from terminal after every boot to mount storage.img
mkdir /sdcard/storage
su
dd if=/dev/zero of=/data/storage.img bs=1024 count=4194340
busybox mkfs.vfat /data.storage.img
mount -o loop -t vfat /data/storage.img /sdcard/storage
Click to expand...
Click to collapse
Thank you, I will use the Thank you button when I login via PC.
I still get the same error, I know that I'm doing something incorrectly or maybe I don't understand "mount" comment correctly?
/ $ su
/ # mkdir /sdcard/storage
/ # dd if=/dev/zero of=/data/storage.img bs=1024 count=41943404194340+0 recordsn
4194340+0 records out
4295004160 bytes (4.0GB) copied, 339.823883 seconds, 12.1MB/s
/ # busybox mkfs.vfat /data/storage.img
/ # mount -o loop -t vfat /data/storage.img /sdcard/storage
mount: can't setup loop device: No such file or directory
/ #
I am using my sdcard also, I'm not too sure if that makes any difference?
Sent from my DROID2 GLOBAL using Tapatalk

Better terminal pro uses BASH shell, I presume
try to switch to android shell, in preferences
or to use terminal emulator (free) from market

Okay, I tried Android Terminal Emulator, and this is a new error.
export PATH=/data/local/bin:$PATH
$ $ su
# mount -o loop -t vfat /data/storage.img /sdcard/storage
ioctl LOOP_SET_FD failed: Device or resource busy
#
Not too sure where to go now. I thank you again for all your help, and time.
Sent from my DROID2 GLOBAL using Tapatalk

resource busy, you have to reboot the phone
I use Gscript lite, add a script with the string
mount -o loop -t vfat /data/storage.img /sdcard/storage
and create a shortcut to homescreen, so when I reboot, I can mount the img file in one click

Cool mod for my ROM. Could I take it??

sure, they are simple shell commands
the best would be to do what happen with Samsung Galaxy S: internal storage mounted as sdcard and physical sdcard mounted in a folder /sdcard/sd
storage.img is 3-4 times faster than my peak 8GB class 6

There is an application "Autostart" in the market, which can automatially execute a script with root after boot up.

I up because I'm now also interested in making profit of the huge internal storage. I'd like to put my wikipedia data from wikidroyd to the internal storage. Hopefully I'm skilled enough to follow the given steps...I doubt that though

fKngFtd said:
Okay, I tried Android Terminal Emulator, and this is a new error.
export PATH=/data/local/bin:$PATH
$ $ su
# mount -o loop -t vfat /data/storage.img /sdcard/storage
ioctl LOOP_SET_FD failed: Device or resource busy
#
Not too sure where to go now. I thank you again for all your help, and time.
Click to expand...
Click to collapse
Guys, I need your help! I have exactly. The same problem:
Every time I try to mount my storage.img I get
Ioctl LOOP_SET_FD failed: Device or resource busy.
I rebooted several times and also tried to mount smaller images (first I tried 3gb then I tried 1mb).
Any solution?
Edit: I solved it myself. I always forgot to punch in busybox before the command. Now it worked for me!!

I do have a question now. With help of Gscript I made a shortcut to mount the storage.img to my sdcard. But my pc wont recognise the sdcard as long as the image is mounted. What is the command to unmount the partition so I wouldnt have to reboot my phone before connecting it to the pc...?
Any help is much appreciated! Thx
(Something like busybox unmount -o loop -t vfat...?)
Sent from my MotoA953 using XDA App

Broken SD card reader help

My HTC Sensation has a broken SD card reader, and I have been reading about mounting an .img file stored on /data to /sdcard/storage but I've tried with no success. What options are there for having something at /sdcard so I can use apps like the camera? It can't be that hard, right?
If you knew something about android partitions, I would love to hear your advice!
Thanks

ketchup539 said:
My HTC Sensation has a broken SD card reader, and I have been reading about mounting an .img file stored on /data to /sdcard/storage but I've tried with no success. What options are there for having something at /sdcard so I can use apps like the camera? It can't be that hard, right?
If you knew something about android partitions, I would love to hear your advice!
Thanks
Click to expand...
Click to collapse
We can use /data partition space for the sdcard.. But we need to setup.. A loop back device..
I'll try to do it on my phone first.. And when I got it working ill give you the steps to do it.. Stay tuned
Sent from my HTC Sensation 4G using xda premium

ganeshp said:
We can use /data partition space for the sdcard.. But we need to setup.. A loop back device..
I'll try to do it on my phone first.. And when I got it working ill give you the steps to do it.. Stay tuned
Sent from my HTC Sensation 4G using xda premium
Click to expand...
Click to collapse
That would be so amazing of you - thanks.
This is what I've done so far without success on CM10:
Code:
mkdir /sdcard/storage
su
dd if=/dev/zero of=/data/storage.img bs=1024 count=5242880 (1024x1024x5 --> 5Gb)
busybox mkfs.vfat /data.storage.img
losetup -d /dev/block/loop0 (this command prevents the "resource busy" error)
mount -o loop -t vfat /data/storage.img /sdcard/storage
This doesn't work because you need an SD card to link a partition to it. If you try it, make sure you remove your sd card.

ohh you are there almost
couple of pointers here
1. dont delete the existing loop devices (-d is to delete)
2. you need to link the loop device to the file you have created
losetup /dev/block/loopx /data/storage.img (x being the available loop number)
busybox mkfs.vfat /dev/block/loopx
3. reduce the size a bit for the storage.img to around 500MB
4. mount the created loop device to the sdcrad mnt point (/mnt/storage.img)
mount /dev/block/loop0 /mnt/sdcard
5. also if loop0 is busy you can try the other loop devices
like loop1,loop2 etc etc
to check the binding type losetup /dev/block/loopx (x being the loop number)
it should give you details of it

Awesome, I'll try this soon. I'm really glad you've come to my help! What is a phone without external storage
Sent from my HTC Sensation using xda app-developers app

Okay, I get this error when I try to mount the image to /mnt/sdcard.
255|[email protected]:/ # mount -o loop4 -t vfat /data/storage.img /mnt/sdcard
mount: Block device required
Sent from my HTC Sensation using xda app-developers app

ketchup539 said:
Okay, I get this error when I try to mount the image to /mnt/sdcard.
255|[email protected]:/ # mount -o loop4 -t vfat /data/storage.img /mnt/sdcard
mount: Block device required
Sent from my HTC Sensation using xda app-developers app
Click to expand...
Click to collapse
You should use -o loop only not -o loop4
Check my previous post again.. I've re edited it
Sent from my HTC Sensation 4G using xda premium

I'm still getting various errors.
[email protected]:/ # losetup /dev/block/loop4 /data/storage.img
[email protected]:/ # mount -o loop -t vfat /dev/block/loop4 /mnt/sdcard
ioctl LOOP_SET_FD failed: Device or resource busy
I don't think I quite understand what a loop is, and I don't know what I'm doing wrong. Could you give me some clear steps so I can start from scratch? Thanks
Sent from my HTC Sensation using xda app-developers app

ketchup539 said:
I'm still getting various errors.
[email protected]:/ # losetup /dev/block/loop4 /data/storage.img
[email protected]:/ # mount -o loop -t vfat /dev/block/loop4 /mnt/sdcard
ioctl LOOP_SET_FD failed: Device or resource busy
I don't think I quite understand what a loop is, and I don't know what I'm doing wrong. Could you give me some clear steps so I can start from scratch? Thanks
Sent from my HTC Sensation using xda app-developers app
Click to expand...
Click to collapse
You did everything correct except the last step
These are the steps
1. Do dd command as you mentioned initially
2. Give the image a Filesystem... The second command you did initially
3.setup a loop device to it...
losetup /dev/block/loopx /data/storage.img
4.then do a simple mount (this is where you did a mistake earlier)
mount /dev/block/loopx /mnt/sdcard
That's all
Note: you should not mention loop and file system type in the mount command again.. That's what causing the issue
Sent from my HTC Sensation 4G using xda premium

For some strange reason, I can't do a simple mount.
[email protected]:/ # mount /dev/block/loop4 /mnt/sdcard
Usage: mount [-r] [-w] [-o options] [-t type] device directory
Sent from my HTC Sensation using xda app-developers app

ketchup539 said:
For some strange reason, I can't do a simple mount.
[email protected]:/ # mount /dev/block/loop4 /mnt/sdcard
Usage: mount [-r] [-w] [-o options] [-t type] device directory
Sent from my HTC Sensation using xda app-developers app
Click to expand...
Click to collapse
Mention the type. And options too
-t vfat -o rw
Sent from my HTC Sensation 4G using xda premium

Okay, so technically it should be mounted at /mnt/sdcard, but the system still can't access it. When I navigate to it with a file explorer it says 'an unknown error has occurred' and no other apps can see it either.
Sent from my HTC Sensation using xda app-developers app

Or else we ditch the complete loop device concept
Do this
1. Using dd make the storage.img
2. Give the files system
3 . Then mount
mount -t vfat -o rw, loop /data/storage.img /mnt/sdcard
Sent from my HTC Sensation 4G using xda premium
---------- Post added at 11:57 AM ---------- Previous post was at 11:09 AM ----------
ketchup539 said:
Okay, so technically it should be mounted at /mnt/sdcard, but the system still can't access it. When I navigate to it with a file explorer it says 'an unknown error has occurred' and no other apps can see it either.
Sent from my HTC Sensation using xda app-developers app
Click to expand...
Click to collapse
Ohh the mount point is the same?
Damn im on sense rom.. I'm not sure how the mount points are defined in cm10
We can find the mount point easily though
Do this
do ll /sdcard
It will give you to what mount point it got linked to
Sent from my HTC Sensation 4G using xda premium

Okay, I suppose you meant 'du’ instead of 'do', because the shell doesnt recognise 'do'. Here is the result:
1|[email protected]:/ # du /sdcard
0 /sdcard
I am very very grateful of your help. If you accept donations I would be more than inclined to give you something for your time.
Sent from my HTC Sensation using xda app-developers app

ketchup539 said:
Okay, I suppose you meant 'du’ instead of 'do', because the shell doesnt recognise 'do'. Here is the result:
1|[email protected]:/ # du /sdcard
0 /sdcard
I am very very grateful of your help. If you accept donations I would be more than inclined to give you something for your time.
Sent from my HTC Sensation using xda app-developers app
Click to expand...
Click to collapse
the command is not do lol
the command is
ll /sdcard
it will give me the mount path
first we'll get this setup and running ..then we'll think of donations

Haha okay.
[email protected]:/ # ll /sdcard
lrwxrwxrwx root root 2012-09-24 17:54 sdcard -> /storage/sdcard0
Sent from my HTC Sensation using xda app-developers app

ketchup539 said:
Haha okay.
[email protected]:/ # ll /sdcard
lrwxrwxrwx root root 2012-09-24 17:54 sdcard -> /storage/sdcard0
Sent from my HTC Sensation using xda app-developers app
Click to expand...
Click to collapse
see the mount point is different
so the final mount command
is
mount -o remount,rw -t vfat /dev/block/loop4 /storage/sdcard0
if the above not working try simpel mount
mount /dev/block/loop4 /storage/sdcard0
if its still not working then we will try another approach ..let me know
EDIT: check your PM
---------- Post added at 01:08 PM ---------- Previous post was at 12:38 PM ----------
Any Update ?

Another thing to add maybe......
Hi guys,
So before I found your attempts, about 3 weeks ago i attempted much the same, however didnt do the whole dd route.
I just did:
mkdir /data/sdcard and then a
mount -o bind /data/sdcard /sdcard
the only issue with that , that i could pick up was
1. filesystem was not vfat (as data is ext)
2. You have more flexible space to play around with, however that too could interfere with /data requirements
3. Even editing the /etc/fstab didnt allow for persistance between reboots. (just a remount required)
Now for questions:
So i have now gone the dd route, mount works , blah blah... BUT - loop dev gets lost after a reboot. anyway of keeping this setting somehow?
That aside - Bonus Material !!
(havent tested this between reboots yet - but
ln -s /dev/block/loop0 /dev/block/mmcblk1p1
and the phone is overjoyed at seeing the SD card where it expects to find it.
k, well my 2c worth, And thanks for the great insight.
J

So you actually got this working? That's amazing! I'd love to help you keep this between reboots, I have some decent ideas on what to do. Let me just get up and try that last command of yours.
Sent from my HTC Sensation using xda app-developers app

Jim.Morrisby said:
Hi guys,
So before I found your attempts, about 3 weeks ago i attempted much the same, however didnt do the whole dd route.
I just did:
mkdir /data/sdcard and then a
mount -o bind /data/sdcard /sdcard
the only issue with that , that i could pick up was
1. filesystem was not vfat (as data is ext)
2. You have more flexible space to play around with, however that too could interfere with /data requirements
3. Even editing the /etc/fstab didnt allow for persistance between reboots. (just a remount required)
Now for questions:
So i have now gone the dd route, mount works , blah blah... BUT - loop dev gets lost after a reboot. anyway of keeping this setting somehow?
That aside - Bonus Material !!
(havent tested this between reboots yet - but
ln -s /dev/block/loop0 /dev/block/mmcblk1p1
and the phone is overjoyed at seeing the SD card where it expects to find it.
k, well my 2c worth, And thanks for the great insight.
J
Click to expand...
Click to collapse
Okay, as for remounting at boot, add a basic script with the commands to remount the card in /etc/init.d, and call it something like 91sdcard. It should look something like this:
Code:
#!/system/bin/sh
commands and whatever
So first off I tried your basic mounting method, and it actually somewhat worked! I could open the camera app, and it thought I had an sd card, but it still couldn't save photos. I guess this is because of the fie system? I could also create files in it through a file explorer. This is the most success I have got since I started to try make a virtual sd card.
I tried to use ln -s /dev/block/loop0 /dev/block/mmcblk1p1 along with my image file and loop devices, but I couldn't get it working for the life of me. Could you elaborate on how you made it work? Thanks

[Q] Xperia L Bootloop after mounting SD card using Link2SD

I am facing trouble in mounting 2nd partition (ext4) of the SD card using Link2SD in Rooted Xperia L. Like many people have faced. I experienced a Boot-Loop. After taking out the partitioned SD card, fortunately the phone boots fine. Even it boots without any problem with non-partitioned SD card, too.
There is unofficial solution of enabling support for init.d using apps like Init.d Toggler.
But, I find that there already an /etc/init.d directory exists. Inside, there are two scripts, viz. 00stop_ric and 11link2sd.
00stop_ric
---------------
#!/system/bin/sh
/system/xbin/busybox pkill /sbin/ric
mount -o remount,rw /
rm /sbin/ric
mount -o remount,ro /
/system/xbin/busybox pkill /sbin/ric
Click to expand...
Click to collapse
11link2sd
--------------
#!/system/bin/sh
#added by link2sd
LOG=/data/link2sd-11link2sd.log
echo "$(date) mounting..." > $LOG
sleep 2
mount -t ext4-o rw /dev/block/
vold/179:34/data/sdext2 1>>$LOG
2>>$LOG
mount -t ext4-o rw /dev/block/
mmcblk1 p2 /data/sdext2 1>>$LOG
2>>$LOG
mount >> $LOG
echo "$(date) mount finished" >> $LOG
Click to expand...
Click to collapse
I failed to find any reference to this problem in the FAQ section of official website.
Should I go for Init.d Toggler solution?
What is causing this problem?
Is 00stop_ric the original mount script of Xperia L?
I solved the problem using Init.d Toggler.
But, I find it surprising why it boot-loop-ed initially, i.e. when init.d was disabled. It could fail to mount the partition, that is acceptable. But, how come just the presence of /etc/init.d/11link2sd script make it boot-loop?
Even before trying Link2SD, I had both /etc/init.d and /etc/init.d/00stop_ric script present. There are the leftover from the Getroot method I applied to root my Xperia. So, neither the phone not having init.d support nor the creation of init.d folder can be the cause of boot-loop.
Definitely, either the presence of /etc/init.d/11link2sd script or something else which we are missing (Developer of Link2SD, Akpinar should be able to correctly answer) is/are the cause of boot-loop.
@Akpinar
Please let us know what Link2SD exactly does while creating Mount script.

@Any Moderator,
Please move this thread to Troubleshooting section. I realized that I have posted in wrong section.

[Completed] Cyanogenmod 12 and 2nd partition in Sdcard

Any one can tell me what I make round. I have cyanogenmod with one sdcard with 2 partitions the first is mount with ext4 and the second I try fat32 ext4 ext3 ...
I no found fuse.ko in the system but internal partition and storage is mount with fuse in /storage/....
I try to mount the second partition by many difference ways . Always is mount and show up
I copy files from internal memory or sdcard first partition to the second partition
But if I try to open the files I got permission errors . Very possible is a Selinux problem but I have in permissive mode
I look with rootexplorer and files a copy in the 2nd partition in the sdcard for the owner only can read or write
Any ideas how to make the correct mounts for the 2nd Partition on SD card
I make a simple script for make test that is the last configuration I make but still only the owner can read or write that means any app can't open the files if is not root
that is the configuration I use
#!/system/bin/sh
# Mount SD Card Ext4 Script
mkdir /storage/sdcard2
mount -r -w -o exec,dev,suid,rw -t ext4 /dev/block/vold/179:66 /storage/sdcard2
mount -r -w -o exec,dev,suid,rw -t ext4 /dev/block/mmcblk1p2 /storage/sdcard2
chown media_rw:media_rw /storage/sdcard2
chmod g+w /storage/sdcard2
ln -s /storage/sdcard2 /mnt/media_rw/sdcard2
ln -s /storage/sdcard2 /mnt/sdcard2
chown media_rw:media_rw /mnt/sdcard2
chmod g+w /mnt/sdcard2

Hi there,
I'm sorry but I can't find anything related to your question.
Please post that in the forum bellow for more answers from the experts:
> Android Development and Hacking > Android Q&A, Help & Troubleshooting
Good luck

Mount external partition using rooted Z3 with locked bootloader

Hello.
I just started messing around with my Z3 and so far followed the tutorial here https://forum.xda-developers.com/z3-compact/general/recovery-root-mm-575-lb-t3418714 to install root and recovery without unlocking the bootloader. Also took the chance to make a backup of the ta partition.
My objective was being able to mount an external ext4 partition so I could move game data and free some internal space. I believe the official kernel doesn't support init.d so I searched and found a script that worked and added it to the bottom of init.qcom.post_boot.sh.
Code:
### Init.d support ###
busybox run-parts /system/etc/init.d/
It's a very simple script that creates /sd-ext folder if it's missing and mounts /dev/block/mmcblk1p2 there
Code:
#!/system/bin/sh
#
# mounts ext partition from sd card
if [ ! -d /sd-ext ];
then
mount -o rw,remount /
install -m 774 -o 1000 -g 1000 -d /sd-ext
mount -o ro,remount /
fi
if [ ! -d /sd-ext ];
then
echo sd-ext not created >> /data/Test.log
else
mount -o rw -t ext4 /dev/block/mmcblk1p2 /sd-ext
fi
It was something that I got on some forum plus some trial and error and some Linux knowledge I have.
It seemed to work. The directory was created and mounted and I was able to move the games there using Titanium Backup.
But after I rebooted, the folder was there and all the data, but the apps don't show up on the apps list. I have to reinstall them...
Am I missing something? How can I fix this?