SD Card From Android Device Rendered Unreadable by Android?

- Removed the 128-gig micro-SD card from my Samsung Note4
(SM-910C, Android 5.0.1)
- Put it into a USB adapter on my PC
- Backed it up to the PC
- Put it back into the Note 4
- Note 4 does not seem to be able to read the card
- Apps that use data on the card seem to hang when
I try to open them.
- Other apps and the phone in general seem to be
hung too after the card has been in there for
a few minutes - only way to re-boot the phone
is to do a battery pull
- I've done the Shut down phone, remove SD card,
restart phone, Settings | System | Storage | Mount
SD Card thing during the window between
rebooting and total system lockup - but no luck.
- When I put the SD card back in the USB adapter and
plug it into my PC, no problem - all the files are
there and Windows seems 100% happy.

Unencumbered by any real knowledge, the only two things
I can think of a

- Windows has done some little thing to the SD card
that makes Android choke on it

- Android needs to go through some one-time scanning/validation
process when the card returns to it's home - and that
process takes a looooong time and takes so much of
some resource that the system seems to hang.... But
I have tried leaving it in that state for at least an
hour and no luck.

Anybody else been here?

--
Pete Cresswell

(PeteCresswell) wrote:
- Removed the 128-gig micro-SD card from my Samsung Note4
(SM-910C, Android 5.0.1)
- Put it into a USB adapter on my PC
- Backed it up to the PC
- Put it back into the Note 4
- Note 4 does not seem to be able to read the card
- Apps that use data on the card seem to hang when
I try to open them.
- Other apps and the phone in general seem to be
hung too after the card has been in there for
a few minutes - only way to re-boot the phone
is to do a battery pull
- I've done the Shut down phone, remove SD card,
restart phone, Settings | System | Storage | Mount
SD Card thing during the window between
rebooting and total system lockup - but no luck.
- When I put the SD card back in the USB adapter and
plug it into my PC, no problem - all the files are
there and Windows seems 100% happy.

Unencumbered by any real knowledge, the only two things
I can think of a

- Windows has done some little thing to the SD card
that makes Android choke on it

- Android needs to go through some one-time scanning/validation
process when the card returns to it's home - and that
process takes a looooong time and takes so much of
some resource that the system seems to hang.... But
I have tried leaving it in that state for at least an
hour and no luck.

Anybody else been here?

The file system could be FAT32 or exFAT.

Using ExFAT might be the "factory" choice for an SDXC card.
Which would require fiddling with, on some phones, in order
to use the storage. Phones are more likely (from a betting
perspective) to support FAT32. A few Android phones don't
support ExFAT.

https://www.androidauthority.com/hig...plains-690710/

"All the other devices I tested (ExFAT) work fine
including the Samsung Galaxy S7, Kindle Fire,
Samsung Galaxy Note Edge (AKA Note 4 Edge),
Asus Zenfone 2, OPPO F1 Plus, and Huawei Mate 8."

https://en.wikipedia.org/wiki/Exfat

"The standard exFAT implementation is not journaled
and only uses a single file allocation table and
free space map. FAT file systems instead used alternating
tables, as this allowed recovery of the file system if
the media was ejected during a write (which occurs frequently
in practice with removable media).
"

https://en.wikipedia.org/wiki/Secure_Digital

"SDXC adopts Microsoft's exFAT file system as a mandatory feature."

If it was me, I'd probably be plugging the device into
a platform that has a copy of "disktype". I have a Cygwin
version of that. I can run it from Linux. There's no
"native" Windows version. And all this software does,
is multiple checks on certain file system characteristics,
with no guarantee it would spot a problem with what was
done.

I wouldn't run Windows CHKDSK on the ExFAT (if that's what
it is), for fear of doing additional damage.

Paul

On 25/08/2018 13:21, (PeteCresswell) wrote:
- Removed the 128-gig micro-SD card from my Samsung Note4
(SM-910C, Android 5.0.1)
- Put it into a USB adapter on my PC
- Backed it up to the PC
- Put it back into the Note 4
- Note 4 does not seem to be able to read the card
- Apps that use data on the card seem to hang when
I try to open them.
- Other apps and the phone in general seem to be
hung too after the card has been in there for
a few minutes - only way to re-boot the phone
is to do a battery pull
- I've done the Shut down phone, remove SD card,
restart phone, Settings | System | Storage | Mount
SD Card thing during the window between
rebooting and total system lockup - but no luck.
- When I put the SD card back in the USB adapter and
plug it into my PC, no problem - all the files are
there and Windows seems 100% happy.

Unencumbered by any real knowledge, the only two things
I can think of a

- Windows has done some little thing to the SD card
that makes Android choke on it

- Android needs to go through some one-time scanning/validation
process when the card returns to it's home - and that
process takes a looooong time and takes so much of
some resource that the system seems to hang.... But
I have tried leaving it in that state for at least an
hour and no luck.

Anybody else been here?


Not exactly, but i have had no end of problems with SD cards in Android
phones - which is why my existing phone has internal memory of 64GB so
that I don't need an additional card.

When you backed up the card in your PC, did you slide the little slider
to make it read-only so that Windows couldn't write to it? If so, have
you put it back to read/write. Android may need to be able to write to
it in order to recognise it.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On Sat, 25 Aug 2018 08:21:18 -0400, "(PeteCresswell)"
wrote:

- Removed the 128-gig micro-SD card from my Samsung Note4
(SM-910C, Android 5.0.1)
- Put it into a USB adapter on my PC
- Backed it up to the PC
- Put it back into the Note 4
- Note 4 does not seem to be able to read the card
- Apps that use data on the card seem to hang when
I try to open them.
- Other apps and the phone in general seem to be
hung too after the card has been in there for
a few minutes - only way to re-boot the phone
is to do a battery pull
- I've done the Shut down phone, remove SD card,
restart phone, Settings | System | Storage | Mount
SD Card thing during the window between
rebooting and total system lockup - but no luck.
- When I put the SD card back in the USB adapter and
plug it into my PC, no problem - all the files are
there and Windows seems 100% happy.

Unencumbered by any real knowledge, the only two things
I can think of a

- Windows has done some little thing to the SD card
that makes Android choke on it

- Android needs to go through some one-time scanning/validation
process when the card returns to it's home - and that
process takes a looooong time and takes so much of
some resource that the system seems to hang.... But
I have tried leaving it in that state for at least an
hour and no luck.

Anybody else been here?

I have a Samsung Galaxy S7 Edge in which I normally use a 64GB microSD
card. I've had no issues moving that card to a Windows laptop to
add/remove files, then moving it back to the phone. Over the past two
years, I've moved it back and forth at least 20 times.

Now that I've said that out loud, the next time will surely fail.

--

Char Jackson

"Char Jackson" wrote in message
...
I have a Samsung Galaxy S7 Edge in which I normally use a 64GB microSD
card. I've had no issues moving that card to a Windows laptop to
add/remove files, then moving it back to the phone. Over the past two
years, I've moved it back and forth at least 20 times.

Yes, I've copied information from an SD card in a Samsung Galaxy S7
(non-Edge) by removing the card and putting it in an SD card reader on
Windows. In my case a couple of files were unreadable on the phone, but were
readable on Windows after several retries. I was able to copy the whole
folder structure off the card, re-format the card in the Android phone, and
then copy all the data back onto it again from Windows. The phone saw all
the files (including the ones that had previously been unreadable) without
any difficulty.

Out of curiosity, I first formatted the card as FAT or FAT32 (I forget
which - whatever it had been before) in the Windows PC and copied the data -
and that also worked but I decided for added peace of mind I'd format the
card again in the phone in case it made any difference.

On Wed, 26 Sep 2018 10:49:14 +0100, "NY" wrote:


Out of curiosity, I first formatted the card as FAT or FAT32 (I forget
which - whatever it had been before) in the Windows PC and copied the data -
and that also worked but I decided for added peace of mind I'd format the
card again in the phone in case it made any difference.

http://www.ntfs.com/ntfs_vs_fat.htm

How big is it ?
[]'s
--
Don't be evil - Google 2004
We have a new policy - Google 2012

"Shadow" wrote in message
...
On Wed, 26 Sep 2018 10:49:14 +0100, "NY" wrote:


Out of curiosity, I first formatted the card as FAT or FAT32 (I forget
which - whatever it had been before) in the Windows PC and copied the
data -
and that also worked but I decided for added peace of mind I'd format the
card again in the phone in case it made any difference.

http://www.ntfs.com/ntfs_vs_fat.htm

How big is it ?

Good point. I'd forgotten about the max partition size of FAT/FAT32. The
card is 64 GB. I've just checked and the filesystem is exFAT. My mistake.

Shadow wrote:
On Wed, 26 Sep 2018 10:49:14 +0100, "NY" wrote:

Out of curiosity, I first formatted the card as FAT or FAT32 (I forget
which - whatever it had been before) in the Windows PC and copied the data -
and that also worked but I decided for added peace of mind I'd format the
card again in the phone in case it made any difference.

http://www.ntfs.com/ntfs_vs_fat.htm

How big is it ?
[]'s

And what does that mean exactly ?

That page has a lot of info, from which a user
might jump to some conclusion.

FAT32 supports up to a 2.2TB volume.

Microsoft OSes imposed an artificial limit of
32GB when formatting FAT32.

The Ridgecrop formatter bypasses that artificial
limit, making more of the 2.2TB maximum available.

http://www.ridgecrop.demon.co.uk/ind...at32format.htm

http://www.ridgecrop.demon.co.uk/dow...at32format.zip

I don't think it's particularly a good idea to use
FAT32 on a 2TB drive to make a single partition.

On the other hand, a slight excursion past 32GB
doesn't hurt anything. A 64GB FAT32 or a 128GB FAT32
would be OK.

The size of the FAT table increases with increasing
volume, but I can't find a handy table of those values.

Version 1.07, according to the release notes, supports
work with GPT partitioned drives.

*******

When an SD is used with mobile devices (like my camera),
it's generally a good idea for the mobile device to
prepare the SD. My camera, for example, doesn't use
bog-standard dimensions for things, and you want your
camera to be happy with an SD, rather than letting the
PC pick any old format for it.

Paul

On 26/09/2018 13:34, Paul wrote:
Shadow wrote:
On Wed, 26 Sep 2018 10:49:14 +0100, "NY" wrote:

Out of curiosity, I first formatted the card as FAT or FAT32 (I
forget which - whatever it had been before) in the Windows PC and
copied the data - and that also worked but I decided for added peace
of mind I'd format the card again in the phone in case it made any
difference.

http://www.ntfs.com/ntfs_vs_fat.htm

Â*Â*Â*Â*How big is it ?
Â*Â*Â*Â*[]'s

And what does that mean exactly ?

That page has a lot of info, from which a user
might jump to some conclusion.

FAT32 supports up to a 2.2TB volume.

Microsoft OSes imposed an artificial limit of
32GB when formatting FAT32.

The Ridgecrop formatter bypasses that artificial
limit, making more of the 2.2TB maximum available.

http://www.ridgecrop.demon.co.uk/ind...at32format.htm

Â*Â* http://www.ridgecrop.demon.co.uk/dow...at32format.zip

I don't think it's particularly a good idea to use
FAT32 on a 2TB drive to make a single partition.

On the other hand, a slight excursion past 32GB
doesn't hurt anything. A 64GB FAT32 or a 128GB FAT32
would be OK.

The size of the FAT table increases with increasing
volume, but I can't find a handy table of those values.

Version 1.07, according to the release notes, supports
work with GPT partitioned drives.

*******

When an SD is used with mobile devices (like my camera),
it's generally a good idea for the mobile device to
prepare the SD. My camera, for example, doesn't use
bog-standard dimensions for things, and you want your
camera to be happy with an SD, rather than letting the
PC pick any old format for it.

Â*Â* Paul



Formatting an SD card with a normal Windows or CMD format command will
often use a totally inappropriate small allocation block size that could
cause slowness and/or excessive wear to the flash memory in the card.

When formatting SD cards on a PC I suggest always using this:
https://www.sdcard.org/downloads/formatter_4/

Or forcing 32K allocation block size if you have to use something else
to format it.

Best bet to get a compatible format for use in a particular device is
generally to get the device itself to format the card if you can.

--

Brian Gregory (in England).