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sdcard2 not writable on Tablet

Posted: 2012-06-24, 10:37 UTC
by NCJuenger
Hi, I've got the Problem that TotalCommander can not write to /mnt/sdcard2. It can open folders but writing simply fails (no error msg). When trying to create a folder I get a message "Folder can not be created".

TC: Version 1.03
Android: 3.2.1 (Honeycomb)
Brand: Toshiba AT200
SD-Card: 16GB SDHC (Class 6)

The included Filemanager (Toshiba Filemanager) can write to SDCard2 and create folders.

Posted: 2012-06-25, 12:50 UTC
by ghisler(Author)
On some devices, the external SD-Card is mounted as read only. Only the included tools can write to it, except if you root the device.

Posted: 2012-06-25, 12:56 UTC
by NCJuenger
Thank you for the answer, this would be a pity but seems plausible.
The tablet is not rooted.

In case I can write with a 3rd party app to the sdcard I will pop up here again.

Posted: 2012-06-25, 19:42 UTC
by holohelge
For information, I have the same problem as NCJuenger.

TC: Version 1.03
Android: 4.0.4 (ICS)
Brand: Medion Lifetab S9512
SD-Card: Medion 16GB SDHC (Class 6)

Posted: 2012-06-28, 12:35 UTC
by ghisler(Author)
Sorry, there is nothing I can do if the file system is mounted as read only.

Posted: 2012-07-02, 13:54 UTC
by NCJuenger
Here's an article which describes the Problem further:
http://www.xda-developers.com/android/android-3-2-code-inadvertently-preventing-write-access-to-external-storage/

It seems to be a "strange" implementation of the WRITE_MEDIA_STORAGE permission. (compared to the WRITE_EXTERNAL_STORAGE permission)

According to Holohelges post this error seems still to exist in ICS.

The only thing TC4Android could do here is to also apply for WRITE_MEDIA_STORAGE Permission (Which it does I suppose). And to hope the OS allows it.

Posted: 2012-08-13, 16:15 UTC
by NCJuenger
I've followed this problem through the forums.

#1: Some Tablet manufacturers (i.e. Samsung) seem to "circumvent" this problem in their android version explicitly.

#2: Currently it seems to help, when the SDCard is formatted with exFAT. I.e. with Windows 7.
Once source:
http://forums.computers.toshiba-europe.com/forums/thread.jspa?threadID=67848&tstart=0

exFAT may not be compatible with other some platforms (MP3-Players, cameras, OS)

how to verify the drive is Read-only mount?

Posted: 2012-08-26, 21:13 UTC
by tochinet
Hi,
I was more than happy to discover that TC was ported to Android. Can't live without it on PC. Still I was disappointed when many copy/Rename actions failed. I'm glad to see this is not due to errors.

One question: how can I verify if the USB or SD is RO-mounted or not?

Posted: 2012-08-27, 06:34 UTC
by NCJuenger
Hi tochinet,
as far as I've learned the sd-card is not simply "RO-mounted" but instead it is a problem of access rights granted to the app or not. The result for TC stays the same anyways.

I know of no standard action to verify the access rights to your tablet. But you can simply install any other third party file manager and try to i.e. copy something on the sd-card. If it also fails this is no problem of TC alone.

This problem mostly applies to tablets. It started with the android version "Honeycomb" (3.x) and persisted on ICS (4.0.x).

Those tablets usually mount the internal flash memory to "/mnt/sdcard". If you insert an sdcard into those tablets those are mounted to "/mnt/sdcard2". And this read/only problem only applies to sdcard2 (the latter).

Usually this error does not occur in the pre-installed file manager supplied by the manufacturer. That one is granted the rights for read/write.

"Rooted" tablets should be able circumvent this problem (if it exists).

And some manufacturers (i.e. Samsung) "hack" their version of android to circumvent this behaviour.

Some people told they had success (at least using some other 3rd party file managers) when formatting the SD-Card to exFAT:
http://en.wikipedia.org/wiki/ExFAT
(This was reported for a toshiba tablet. I'm unsure whether every manufacturer includes fs-drivers for exFAT)

Posted: 2012-08-30, 08:57 UTC
by tochinet
Hi NCJuenger,

I tried ES file explorer, failed. File Browser, success. So 100% correct.

I noticed we have the same tablet (Lifetab 9512). BTW it seems it also lacks the "Format SD card" option in the settings (just below the unmount on a samsung phone).

This seems a bug more than anything else. How can I then backup stuff from the tablet ?

Posted: 2012-08-30, 10:23 UTC
by NCJuenger
Hi tochinet,
I don't own a Lifetab. I have a Toshiba AT200 (also known as Excite 10 LE).

About backup:
If you want to use the total commander you can still copy files via wifi to Network Shares. Maybe also to external storages connected via USB (or USB-To-Go) if the Lifetab has an USB-Host or USB-To-Go connector.

You could also try to format (on a pc with a card reader) the MicroSD with exFAT. (If you have a computer with XP there's an update (KB955704) available which should add support, vista and 7/8 support exFAT out of the box). Maybe exFAT is a special case for tablets which support (micro)SDXC-Cards as exFAT is the proposed FS for SDXC. And I don't know if the Lifetab supports SDXC.

Posted: 2012-08-31, 12:04 UTC
by NCJuenger
I can now acknowledge: Formatting with exFAT works!
(on my Toshiba AT200 Tablet running ICS)

I formatted a microSD to exFAT. I used a Windows XP computer with KB955704 installed (exFAT is included in Vista / Windows 7) for formatting. The microSD was with an SD-adapter in a card reader.

Total Commander (Android) could read & write to the card.


I have no idea why this is so, but it works.

Posted: 2012-09-07, 16:41 UTC
by siscoman
NCJuenger wrote:I can now acknowledge: Formatting with exFAT works!
(on my Toshiba AT200 Tablet running ICS)

I formatted a microSD to exFAT. I used a Windows XP computer with KB955704 installed (exFAT is included in Vista / Windows 7) for formatting. The microSD was with an SD-adapter in a card reader.

Total Commander (Android) could read & write to the card.


I have no idea why this is so, but it works.
Same problem here with a Zopo device, what is a exfat?

Posted: 2012-09-07, 17:37 UTC
by ghisler(Author)
I found some multimedia functions which provide limited write access to the SD-Card. These functions are now built into TC/Android 2.0. Please test it, but make a backup of the card before trying to delete any files!

You can find the first beta here:
http://ghisler.ch/board/viewtopic.php?p=255091

Posted: 2012-09-08, 21:44 UTC
by NCJuenger
Hi Christian Ghisler,
I tested the beta with a Fat32 SD-Card in my Toshiba AT200 (4.0.3).

Copying picture files from internal flash to sdcard2 basically works.
Creating folders works.
Deleting files works.

Copying a folder from internal flash (/mnt/sdcard) does not work. (You can still create the folder via menu, change into the folder and copy the files then)

Copying files from the lan (SMB) does not work. (No error msg, simply fails)



hi siscoman,
exFAT ist a way (filesystem) to format a SDCard. Like FAT32 or NTFS. When you format the memory card on a windows computer you can choose the file system. On Vista or Windows 7 you can directly select exFAT.

On Windows XP Computers you need to install an update from microsoft before called KB955704:
http://www.microsoft.com/en-us/download/details.aspx?id=19364

Please note that you will loose all data on the card when formatting it. I can not say if your "Zopo device" supports exFAT. This may be different from device to device. Perhaps you have a smaller (micro)SD Card at hand to experiment with.