Database Info

failed to mount /data

SOLVED
I rooted my s7 and installed twrp. I tried to do a nandroid backup in twrp and got the message that it couldn't mount /data. It turns out that by not performing the data format step in http://forum.xda-developers.com/galaxy-s7/development/recovery-official-twrp-herolte-t3333770 TWRP couldn't access /data. I did the steps over again and all was well.

kettir said:
I've rooted my s7 and installed twrp. I tried to do a nandroid backup in twrp and got the message that it couldn't mount /data.
I do have root, twrp does run when I boot into recovery. However, whether I select to allow modifications to system or not, twrp does not see the internal sd card.
I followed these instructions to root: http://forum.xda-developers.com/galaxy-s7/development/recovery-official-twrp-herolte-t3333770
However, I did not do step 10:
Only if you want internal storage or data to work in TWRP:
Go to [Wipe] -> [Format Data] (not advanced wipe) -> type "yes".
WARNING: This will wipe your internal storage, disable encryption, and factory reset your phone!
Go to [Reboot] -> [Recovery].
Is this the reason that I can't access internal storage? If it is, I can go ahead and do the format data thing. I just would like to know if that is probably the reason I'm having this problem. NOTE: The phone is not encrypted so far as I know.
Click to expand...
Click to collapse
Internal data is encrypted nevertheless. Only a format will remove this encryption and it is the only way that you can make a TWRP backup of this data.

Bright.Light said:
Internal data is encrypted nevertheless. Only a format will remove this encryption and it is the only way that you can make a TWRP backup of this data.
Click to expand...
Click to collapse
Frag. Well, in that case, I've already installed TWRP, so presumably I can just boot to TWRP, swipe right to enable changes, format data, flash supersu, and then flash dm-verity and force encryption disabler. Then go through the setup again.
If I could have my way, someone would disable the security deal with writing to the SD card, the phone could be purchased pre-rooted, and I wouldn't have to worry about bricking my phone every time I flash something.
Rant over.

@kettir: You're exactly right!
btw: The security deal is not over when you root your phone. 'I still haven't found what I'm looking for' is a very precise song for this problem.

I had the same issues and succesfully used the sequence proposed by Kettir:
- Enable OEM unlock
- ODIN: Install TWRP
- TWRP: Wipe -> Format data
- TWRP: flash supersu
- TWRP: flash dm-verity and force encryption disabler

Did not decrypt internal storage prior to installing TWRP

I installed TWRP successfully, but because I'm an idiot, I didn't decrypt my internal storage first. This has put me in a situation where TWRP cannot access or mount internal storage, and the tablet won't boot to OS so I can decrypt it from the GUI. Can someone suggest something please? Thanks!

How do you backup with TWRP given the issues caused by dm-verity?

I have a J710DM/DS. I flashed the latest version of TWRP (TWRP for j7xelte - 3.0.2.1) with no problems.
But when I try to do a backup (to the external SD card), I get the expected "failed to mount /data" errors that result from dm-verity.
TWRP's website talks about this and mentions that some versions have a "System Image" option, but I don't see it on my phone.
So how do I properly do a backup?

This is nothing to do with dm-verity, it's encryption.
Format DATA to remove encryption and then install the boot patch.
My builds of TWRP have image backup, but not sure if I've compiled a j710 version.

ashyx said:
This is nothing to do with dm-verity, it's encryption.
Format DATA to remove encryption and then install the boot patch.
My builds of TWRP have image backup, but not sure if I've compiled a j710 version.
Click to expand...
Click to collapse
Thanks for the information.
What boot patch?
Edit:
Also, what's the recommended way to format DATA? If TWRP can't even mount it, can it even format it?

Haphim said:
Thanks for the information.
What boot patch?
Edit:
Also, what's the recommended way to format DATA? If TWRP can't even mount it, can it even format it?
Click to expand...
Click to collapse
FORMAT *not* WIPE. You don't need to mount to FORMAT.
To disable forced encryption and mount internal storage:
(Note this MUST be flashed after SuperSU if you intend to root)
1. Boot to Twrp
2. Format Data partition using FORMAT DATA button under Wipe options.
(Note: This will wipe the internal storage)
3. Check DATA is mountable.
4. Install SuperSU (if root is required)
5. Install boot image patch below.
6. Reboot
Boot image patch
no-verity-no-encrypt_ashyx

ashyx said:
FORMAT *not* WIPE. You don't need to mount to FORMAT.
To disable forced encryption and mount internal storage:
(Note this MUST be flashed after SuperSU if you intend to root)
1. Boot to Twrp
2. Format Data partition using FORMAT DATA button under Wipe options.
(Note: This will wipe the internal storage)
3. Check DATA is mountable.
4. Install SuperSU (if root is required)
5. Install boot image patch below.
6. Reboot
Boot image patch
no-verity-no-encrypt_ashyx
Click to expand...
Click to collapse
Thank you so much for elaborating!
Quick follow-up: I have already flashed SuperSU previously. Will I need to flash it again after formatting DATA?

Haphim said:
Thank you so much for elaborating!
Quick follow-up: I have already flashed SuperSU previously. Will I need to flash it again after formatting DATA?
Click to expand...
Click to collapse
You will need to reflash supersu.

Quick, but vital question:
Does flashing "no-verity-no-encrypt_ashyx" mean that I can now safely restore a full system backup?

Haphim said:
Quick, but vital question:
Does flashing "no-verity-no-encrypt_ashyx" mean that I can now safely restore a full system backup?
Click to expand...
Click to collapse
If you made a backup of an unencrypted data partition then you can restore if /data is mountable.
If you are not restoring /data then it doesn't matter.

Thank you so much for helping me understand all of this. You're the best!

phone storage won't show in file explorer when in TWRP

I'm having an issue seeing the phone when booted in TWRP through the fastboot command. I want to be able to copy the magisk zip on to the storage. Anny help would be appreciated!

You are using a twrp version which also decrypts /data?
If not then you don't indeed see internal storage :good:

I changed my security from a pin to a password, entered the password when prompted in TWRP and I got everything to work!

[HELP NEEDED] Cannot access internal storage from Recovery

Here's what I have done so far:
1. Set up MIUI with a pattern lock. Haven't done anything explicitly that will encrypt internal storage.
2. Applied for bootloader unlock.
3. Unlocked bootloader.
4. Flashed TWRP to recovery from Fastboot, then booted into TWRP
5. Formatted /data from TWRP
6. Rebooted to TWRP
7. Wiped /data, /internal, /dalvik, /cache
8. Flashed crDroid (A10).
Here is where the problem begins. I set up crDroid without any passcode or screen lock. But the internal storage is still encrypted. Now when I boot into TWRP, the internal storage is not accessible. Same with PBRP. Trying to wipe Internal Storage from PBRP makes it reboot. The log from PBRP is attached here.
How do I decrypt the internal memory so that I can access it via TWRP/PBRP? Formatting /data doesn't seem to solve anything at all.
The reason I want to decrypt internal memory is because I want an absolutely clean crDroid install with no prior data hanging around anywhere in the system.