How to recover a sd card memory after telling Android to forget it

[Android Central Question]

Hi. I had a memory and it was set to be my internal storage (android 9), then I lost the memory with no hope of getting it back, so I told android to forget about the memory (the storage settings kept prompting me to either insert the memory or forget it). But I miraculously found it and insert it. It no longer worked, Android and windows all alike said the memory card needs formatting to be used. So I ran a chkdsk :/f command and it returned: "raw file system, cannot access it." Then I tried to recover my files with a couple of recovery softwares, like EaseUs and iCareRecovery. But all those recovery tools recovered were some totally useless files that I don't need at all. I've got some important records and pictures in that device that I need to get back.

 

[anon(10614692)]

The SD card will be encrypted, anyway. The only way to access the info is through the phone itself. If the card is corrupt, it's end of story. This is why we do not recommend adoptable storage as the extensive read/write operations and possible corruption render the card useless.

 

[Mooncatt]

The SD card will be encrypted, anyway. The only way to access the info is through the phone itself. If the card is corrupt, it's end of story. This is why we do not recommend adoptable storage as the extensive read/write operations and possible corruption render the card useless.

Even if the card wasn't corrupted, telling your phone to forget it would mean deleting the encryption key and data would not be recoverable anyway.

But I'm slightly confused. Was the card actually formatted as internal storage? If so, you shouldn't have been able to remove it in the first place without causing other issues than that simple notice. If you would register an account here so you can rely and clarify exactly what happened and how the card was formatted in the phone (internal or external storage), it may help us find a solution. If the card was encrypted at all (which it sounds like it may have been), then I'm afraid you may be out of luck unless you had those files backed up somewhere.

 

[anon(10614692)]

Sorry, OP, I have read your post again. You state you told the phone to forget the card you set up as adoptable storage. This means the encryption key needed to decrypt your data is gone. The result will be you have no chance of data recovery

 

[Rukbat]

The card isn't formatted as a card, but as internal storage - which looks nothing like an SD card, an SSD or a HD - it's a totally different format that looks, to any computer, like an unformatted SD card.

But once you told the phone to forget the card, there's no way to tell it "remember the card now". It doesn't keep a record of what's located where on the card once you tell it to forget the card. (And, unlike an external format, there's no directory structure on the card - the directory structure is in eMMC [internal] storage. If you lost that, because it was on the card, you'd be - at best - in Recovery when you turned the phone on. Android would be gone.)

 

[amin021023]

Even if the card wasn't corrupted, telling your phone to forget it would mean deleting the encryption key and data would not be recoverable anyway.

But I'm slightly confused. Was the card actually formatted as internal storage? If so, you shouldn't have been able to remove it in the first place without causing other issues than that simple notice. If you would register an account here so you can rely and clarify exactly what happened and how the card was formatted in the phone (internal or external storage), it may help us find a solution. If the card was encrypted at all (which it sounds like it may have been), then I'm afraid you may be out of luck unless you had those files backed up somewhere.

Yes the sd card was formatted by my Android device to be used as internal storage the first time I inserted it after buying it. By internal storage, it didn't mean internal storage as such, Android asked me if you want to use the card as a media and cross devices or do you want to use it only on this device. I told it I only want to use it on this device. And I didn't encounter any problem when I remove the card, my apps are intact and all working with no problem, Android must have installed them on the device's original internal memory.

 

[belodion]

All is lost, alas.

 

[amin021023]

The card isn't formatted as a card, but as internal storage - which looks nothing like an SD card, an SSD or a HD - it's a totally different format that looks, to any computer, like an unformatted SD card.

But once you told the phone to forget the card, there's no way to tell it "remember the card now". It doesn't keep a record of what's located where on the card once you tell it to forget the card. (And, unlike an external format, there's no directory structure on the card - the directory structure is in eMMC [internal] storage. If you lost that, because it was on the card, you'd be - at best - in Recovery when you turned the phone on. Android would be gone.)

Android was intact now and when I removed it. When I first bought and inserted the sd card Android asked me: do you want to use the card as a media and cross devices or do you want to use it only on this device. I told it to format it in a way that I use it only on this device. And then I told Android to forget it.

 

[amin021023]

All is lost, alas.

You mean there's no chance of de-encryption or conversion or recovery at all?

 

[amin021023]

The strange thing is that back then when I had the card and all was good, there occasionally appeared large files with swf format that I had no idea where it came from or what a swf file is. And now that I tried recovery with some windows softwares, they come up along with some other useless files that I wasn't looking for.

 

[amin021023]

Sorry, OP, I have read your post again. You state you told the phone to forget the card you set up as adoptable storage. This means the encryption key needed to decrypt your data is gone. The result will be you have no chance of data recovery

Is it not possible to recover the keys on my device's original internal storage by rooting the device and using recovery softwares?

 

[Mooncatt]

Is it not possible to recover the keys on my device's original internal storage by rooting the device and using recovery softwares?

Unlikely, even with forensics level recovery tools. Encryption is designed to protect privacy of sensitive data, so deleting the encryption key is a complete deletion. The original file data may still be on the card, but in a jumbled mess that can no longer be read due to the lack of the key.

 

[belodion]

You mean there's no chance of de-encryption or conversion or recovery at all?

I do mean that, yes, except that I'd soften it slightly by saying 'no practical or realistic chance'.

 

[Rukbat]

The encryption key could be calculated from things like the timestamp at the time it was created (and stored encrypted by some other encryption method). But when you tell it to forget the encryption, it's gone. Even if you could remember exactly (in human terms) when you created it, the timestamp is at least granular to the second (and it might be granular to the microsecond - even system developers don't worry about things like that, we just use the timestamp, and extract whatever part we need for the situation we're working on). Eventually, it's going to get granular to the nanosecond. But even if it's only granular in Android to the second, the hash of two timestamps a second apart would be totally different.

 

[Gary Seven]

Hello, I'm new here and joined up specifically to add to this post..
Because the same thing happened to me while on vacation.
My SD card began to store corrupted photos and so I swapped it out
for a spare I was carrying, but the phone (Android 10) wouldn't recognize the new card
prompted me to forget the old one before it recognized the replacement !!
Now I'm stuck with the horrible loss of some really important pictures.
Surely this must have happened to thousands of Android users by now
and should be worked on to find a solution. Even having a "Forget" feature
seems to be one security measure too many in my opinion, I see little point
in it other than to annoy people.
Google should create a secure site where can verity who we say we are and
get our cards decrypted. it must be possible to generate a method of recovery.
The title of this post is "How to recover a sd card memory after telling Android to forget it"
So far this question hasn't been answered.. "All is lost" isn't the solution.

 

[Mooncatt]

Hello, I'm new here and joined up specifically to add to this post..
Because the same thing happened to me while on vacation.
My SD card began to store corrupted photos and so I swapped it out
for a spare I was carrying, but the phone (Android 10) wouldn't recognize the new card
prompted me to forget the old one before it recognized the replacement !!
Now I'm stuck with the horrible loss of some really important pictures.
Surely this must have happened to thousands of Android users by now
and should be worked on to find a solution. Even having a "Forget" feature
seems to be one security measure too many in my opinion, I see little point
in it other than to annoy people.
Google should create a secure site where can verity who we say we are and
get our cards decrypted. it must be possible to generate a method of recovery.

Welcome to the site. I've never had a phone ask to forget a memory card, and always able to swap around. Was yours formatted as internal storage?

 

[hallux]

I have also not heard of that feature. Please be aware that how SD cards are handled may be something the device manufacturer developed, not Google, so the support of that (including having some recovery option) would be on the device manufacturer rather than Google or Android.

horrible loss of some really important pictures

I'm sorry if this comes off as rude, inconsiderate or unsympathetic, but it's true and it's lesson EVERYONE learns at some point. I'm going to paraphrase something a former co-worker used to say. Those pictures were important? Surely you can recover them from the backup then. "Important" information, be it pictures or other data, should NEVER be trusted to a single storage location. My irreplaceable data is stored in no less than 3 places (including one not in my home), with photos from trips I've taken stored in FOUR places.

 

[B. Diddy]

Welcome to Android Central! It sure sounds like you had formatted your SD card as Internal Storage. We generally recommend against using SD cards this way, because SD cards are inherently much less reliable than onboard storage. SD cards are best used as Portable Storage only, and even then, as hallux indicated, any important data stored on the card should be backed up or synced somewhere safe on a regular basis.

When you format a card as Internal Storage, it gets encrypted to be used with that phone only -- if you tried using it in another device, it won't be recognized at all. This is necessary, since the card has essentially become part of the phone's internal storage, and needs to be protected against modification by any other device. Encryption means that he phone that encrypted it holds the one and only encryption key. If something happens to that phone (or if you tell the phone to forget that card, and hence that encryption key), then all of the data on the card is useless.

 

[Deborah Fatuyi]

Hi, I had the same problem with my SD card, I mistakenly asked my phone to forget it. But now I could not access the SD card any more both on the phone and when using a card reader. The SD card is not visible to any device. Can this be rectified or I've lost the card completely

 

[tismydroid]

Hi, I had the same problem with my SD card, I mistakenly asked my phone to forget it. But now I could not access the SD card any more both on the phone and when using a card reader. The SD card is not visible to any device. Can this be rectified or I've lost the card completely

You may benefit by reading the answers already provided in this thread. But the quick answer is... Yes, you have completely lost the info that was once stored on that card.