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Questions about "wiping" data

Ok, with all of the talk about making sure folks do a full wipe before installing ICS, I would like to get some clarification on all of the different wiping methods and which is the best way...
I know of these ways:
1. Via custom recovery - you can wipe data, system, cache, etc.. individually.
2. Via holding Power+VolumeDown until bootloader text appears,, then wait until menu appears and select the Wipe Data option (instead of the cold boot option).
3. Via AARD SuperWipe full script
And then of course, there is the "Reset to factory defaults" in the OS itself...
Which is the best to use? I would assume the AARD SuperWipe full would be the most thorough as it recreates the partitions and everything (instead of just formatting them).
FOr users that have the ability, would an NVFlash of the OS be "more thorough" than CWM method?
Opinions/Experiences?
Thanks!

Don't use super wipe script. A lot of people reported having problems of some ROMs not flashing correctly after using it. There is no reason to use the "full" version anyway. It formats the /media partition(your internal storage partition) which you don't want to nor need to format.
Wipe Data in your #2 does pretty much the same thing as "Reset to factory defaults". They both wipe /data and /cache but do not touch /system.
The most thorough way of wiping that I use is via CWM.
I do all of this within CWM if I want to ensure a clean install of a new ROM and it has never failed.
- wipe data/factory reset
- wipe cache partition
- advanced / Wipe Dalvik Cache
- Mounts and Storage / format /system
I am not sure how NVFlashing a ROM does a clean install? As far as I know, it just flashes whatever it's told to flash. It wouldn't even touch /data if you were just flashing a ROM with it.

horndroid said:
Don't use super wipe script. A lot of people reported having problems of some ROMs not flashing correctly after using it. There is no reason to use the "full" version anyway. It formats the /media partition(your internal storage partition) which you don't want to nor need to format.
Wipe Data in your #2 does pretty much the same thing as "Reset to factory defaults". They both wipe /data and /cache but do not touch /system.
The most thorough way of wiping that I use is via CWM.
I do all of this within CWM if I want to ensure a clean install of a new ROM and it has never failed.
- wipe data/factory reset
- wipe cache partition
- advanced / Wipe Dalvik Cache
- Mounts and Storage / format /system
I am not sure how NVFlashing a ROM does a clean install? As far as I know, it just flashes whatever it's told to flash. It wouldn't even touch /data if you were just flashing a ROM with it.
Click to expand...
Click to collapse
I've tried ALL of the above methods - all with the exact same results, to be honest...
Even if I revert back to honeycomb (even after a full wipe), I STILL exhibit the reboot issues (it's not just me - look around). This was NOT happening before with the exact same version of Revolver. This tells me that there is still yet something else that was changed during the ICS updates. We know the bootloader was updated - i'm now testing ICS with the old bootloader.
Other than the bootloader, what else could have changed?? Unless they upgraded the firmware on a particular device during the ICS update (wifi chip, bluetooth chip, etc). Other than that, I just can't come up with an explanation as to why Honeycomb won't even run properly anymore!
Sent from my Transformer TF101 using Tapatalk

horndroid said:
I am not sure how NVFlashing a ROM does a clean install? As far as I know, it just flashes whatever it's told to flash. It wouldn't even touch /data if you were just flashing a ROM with it.
Click to expand...
Click to collapse
If you use the --create flag, nvflash will format ALL the partitions and then flash them. If you use the --download flag, it will just overwrite the partitions you send it.
That being said, I agree at your wiping method is more than enough. Most times, I don't bother wiping, especially data.
sent from my cyanogen(mod) vision

[Q] TF101 Installing Custom ROM on Encrypted device

I recently managed to successfully root my TF101.
I installed CWM (Via ROM Manager) and downloaded CM9
I boot into CWM and attempt to do a nandroid...can't find path.
I attempt to just install from SDCard...can't find path
Realization (and research) hits that CWM can't see the external sd, and the system doesn't see it as SDCARD but EXT-.
CWM can't see the internal SDCard because apparently on the Tablet the ICS encryption locks that down (but doesn't on my EVO since the SC Card isn't part of the internal storage)
I attempt to perform a factory data wipe to clear out the encrtyption , but upon reboot CWM loads. I try to perform the boot-launcher data wipe, but then CWM loads.
I try to use CWM to factory reset but since it can see the damned SDCard because of the encryption, no dice.
My machine is not bricked, as I can still boot into the previous install but I can't seem unable to format the thing to install CM9.
What to do, and thanks.

It has been said multiple times before DO NOT USE ROM MANAGER.
Either use Thing O Doom's peri to install a different CWM or Gnufabio's Recovery installer or NVFlash a rom to completely wipe. And don't use encryption there is no point 99% of the time

I didn't check here first, which is obviously what was my first mistake.
Will any of those recoveries be able to access and format the SD Card area?
Also, I use encryption as I do have sensitive things on my machine that I don't want exposed in case the machine is stolen. First time I've ever had it give me a problem, as the phone encrypts differently.

Team roug's recovery has internal and external sd support and i think the encryption is an ics/tegra 2 bug more than anything

Ok, so I managed to get the new recovery on via Thing O Doom's peri. And I was able to install Revolver via the ext card...but upon boot I was prompted for my encryption pin and got the message that android was updating...My Build number is now Revolver but everything is the same as it was. I still can't factory wipe this damned thing.
Upon request to wipe, it boots back to recovery and says formatting data and cache, data wipe failed.
Tis site states http ://0xfeedface.org/blog/lattera/2012-06-04/installing-cm9-encrypted- android-tablet
The dilemma
When you encrypt your Android device, the /data partition is what gets encrypted. The partition in full is encrypted and cannot be mounted within CWM. CWM also cannot perform a wipe, since it cannot mount the /data partition. And CWM cannot mount the external SD card. This is our dilemma. No access to the internal SD. No access to the external SD. No way to perform a wipe and format the internal SD from CWM.
The Solution
What we need to do, then, is use adb while the tablet is in recovery mode to reformat the internal SD card, thereby removing the encryption. On the US Transformer Prime, the internal SD card is at /dev/block/mmcblk0p8. The partition for our spare SD card will be at /dev/block/mmcblk1p1. You will need to replace those device entries for any other device you might attempt this on. After formatting the internal SD card, we will mount it and then mount the external SD card at /data/media:
In CWM, wipe cache
adb shell
mke2fs -t ext4 /dev/block/mmcblk0p8 # Warning: This can take a while. Be patient.
mount /data
mount /dev/block/mmcblk1p1 /data/media
Now go back to CWM on your device, then go ahead and flash your CM9 and gapps zips like normal. You now have CM9 installed! The /data partition is not encrypted. If you do not need to flash any other ROMs (unlikely if you're reading this article), feel free to re-encrypt your device.
Click to expand...
Click to collapse
I don't know the block numbers for the TF01

you need to undo the encryption before you can wipe anything

You can't. Hence my problem. I cannot mount,delete, or format the SDCard. It sounds like the process in the above post is the solution, but I don't know how to find out what block numbers the tf101 uses.

If you don't mine losing your data NVflashing a rom will resolve all the problems

Yep nvflash will do the trick otherwise as the solution you found yourself explains
Use adb in recovery ( in other words hook it up on a pc ) for this you will need android sdk runnin on your pc
More info about adb u can find here
http://forum.xda-developers.com/showthread.php?t=1751439&highlight=adb+help
Good luck

Thanks to all, I have resolved my issue!
I had to download the stock rom, extract the blob, and use Wheelie for PC to NVFlash everthing abck to stock. I was then able to update over OTA, and use the excellent Thing O Doom's peri to re-root and flash the working recovery.
There should be several items in the Root FAQ up top, such as:
If you are encrypted and going to root, factory reset to get rid of the encryption FIRST since the encryption locks down the SDCARD partition (Unlike on the phone)and none of the recoveries can access it to mount. DON"T use ROM manage on the TF101 and always, always check XDA first.
:good:

darthrater said:
Thanks to all, I have resolved my issue!
I had to download the stock rom, extract the blob, and use Wheelie for PC to NVFlash everthing abck to stock. I was then able to update over OTA, and use the excellent Thing O Doom's peri to re-root and flash the working recovery.
There should be several items in the Root FAQ up top, such as:
If you are encrypted and going to root, factory reset to get rid of the encryption FIRST since the encryption locks down the SDCARD partition (Unlike on the phone)and none of the recoveries can access it to mount. DON"T use ROM manage on the TF101 and always, always check XDA first.
:good:
Click to expand...
Click to collapse
That FAQ is sadly pretty outdated, I wish I could liberate the OP
Glad all is working now though.

[Q] Internal Data Wipe pre Rom Flash

I am curious about doing an internal data wipe before flashing a new Rom. I am using TWRP 2.5.5. I am on the 4.2 bootloader and am about to update to the new CROMi. I know that doing a factory reset wipes dalvik, cache, and system, am I wrong in thinking this still leaves some stuff left over on your internal SD? If it does, I want to format all of it. I have the 4.2.1 bootloader, the CROMi rom, and a 4.2.1 stock nandroid backup I made in TWRP all saved on my external SD. What I dont understand is if I format all the data on the internal, how will the tablet know what to do when I boot it back up? Will TWRP be lost? If it does boot back up, what will it boot back up to? I just dont quite understand this internal SD formatting thing so well, so I am asking for some help so I can avoid doing something stupid. I know this is possible because I have read about other people doing it in the CROMi thread, I just want to make sure I am not missing anything

Your tablet has the following partitions (and some others which are irrelevant for this discussion):
- Bootloader
- Recovery
- Linux kernel
- Cache partition (/cache)
- System partition (/system)
- Data partition (/data)
The internal SD card is an emulation that uses /data/media as storage. So if you format /data, that removes all user data including the contents of your "internal SD card" emulation. I don't know why the normal "factory reset" somehow deletes only the rest of /data excluding /data/media. It may be convenient but not what I would understand as "factory reset".
If you format /system (which is not touched by a factory reset), you won't be able to boot Android unless you install a new ROM before you reboot. You don't need to format /system, it's done by the CROMI installer anyway.

_that said:
Your tablet has the following partitions (and some others which are irrelevant for this discussion):
- Bootloader
- Recovery
- Linux kernel
- Cache partition (/cache)
- System partition (/system)
- Data partition (/data)
The internal SD card is an emulation that uses /data/media as storage. So if you format /data, that removes all user data including the contents of your "internal SD card" emulation. I don't know why the normal "factory reset" somehow deletes only the rest of /data excluding /data/media. It may be convenient but not what I would understand as "factory reset".
If you format /system (which is not touched by a factory reset), you won't be able to boot Android unless you install a new ROM before you reboot. You don't need to format /system, it's done by the CROMI installer anyway.
Click to expand...
Click to collapse
Aweomse! Thanks for helping me understand that a little better. My first ROM was CROMi 3.4.4 and I researched all this for about an entire week before I started this but I never fully understand the difference with formatting internal SD and factory reset. I have always installed the new ROM before rebooting anyway but it is nice to know CROMi does the system wipe for you. Didnt know that. If I were to do a complete wipe, would I need to install the most recent 4.2 bootloader prior to installing CROMi so it is there for CROMi to build on?
Oh, and btw your Kernels for CROMi are outstanding.

Turin87 said:
My first ROM was CROMi 3.4.4 and I researched all this for about an entire week before I started this but I never fully understand the difference with formatting internal SD and factory reset.
Click to expand...
Click to collapse
There is even official TWRP documentation about wiping: http://teamw.in/whattowipe
(I personally have never used any of the wipe options so far, so I am just repeating what I read about it)
Turin87 said:
If I were to do a complete wipe, would I need to install the most recent 4.2 bootloader prior to installing CROMi so it is there for CROMi to build on?
Click to expand...
Click to collapse
There is no "wipe bootloader" option, so there is no need to reinstall the bootloader. Wiping the bootloader would also brick your device and you would need nvflash to recover.

_that said:
There is even official TWRP documentation about wiping:
(I personally have never used any of the wipe options so far, so I am just repeating what I read about it)
There is no "wipe bootloader" option, so there is no need to reinstall the bootloader. Wiping the bootloader would also brick your device and you would need nvflash to recover.
Click to expand...
Click to collapse
Good to know. Glad I didnt attempt that. My firmware version was .30 so nvflash was not an option for me. Thanks again for your help.

[Q] encrypted tablet, "factory data reset" not working

Hey all. I have a rooted TF700 with CM 10.2 on it. I have encrypted the tablet (via SETTINGS - SECURITY - ENCRYPTION). I'd like to do a "Factory Data Reset" - it's my understanding that this will remove the encryption, along with all my user data. This is what I'd like to do.
However, when I go to SETTINGS - BACKUP & RESET - FACTORY DATA RESET, it doesn't work. It asks me to enter my password, then asks me to 'erase everything', and when I click it, it reboots as if to perform the reset. I get the little android guy after it reboots, then the ASUS screen, then CM boot screen. However, the tablet boots like normal, is still encrypted, and all my user data is still there.
I recently upgraded from CM 10.1 to 10.2 - getting the gapps package to install took several tries for some reason, but eventually it worked. I have clockwork recovery installed, but because the tablet is encrypted I am unable to mount or format the /data partition from clockwork.
Anyone have a clue how I can get the 'Factory data reset' to work, or otherwise decrypt my tablet? Thanks!

Factory reset is done by your recovery. Which recovery (and version) is currently installed? Maybe you need to choose "format data" explicitly in the recovery.

_that said:
Factory reset is done by your recovery. Which recovery (and version) is currently installed? Maybe you need to choose "format data" explicitly in the recovery.
Click to expand...
Click to collapse
I cannot touch (either mount or format) /data from Clockwork recovery because it is encrypted by android. any attempt to do so, and I get an error
"ERROR cannot (mount/format) /data!"
doing the 'Factory Data Reset' from within Android is supposed to decrypt and wipe /data, but that is not working.

I flashed TWRP and got rid of Clockwork recovery - that enabled me to mount /data in recovery (TWRP asks for my password to decrypt /data when TWRP starts), which is something. However, when I go into /data using the terminal I only see the lost+found directory and nothing else?
However, formatting /data from TWRP doesn't work, neither does a reset. They just give me errors.
I then tried abd shell - mke2fs -T ext4 /dev/block/mmcblk0p8
but that gives me a '/dev/block/mmcblk0p8 is apparently in use by the system; will not make a filesystem here!' error, even after unmounting it manually (umount -a)
Next, I tried using TWRP to reinstall CM 10.2. After that, the boot process took 40 minutes or so. Once it came up, there was no user data and cyanogenmod was fresh (yay!) - but the partition is still encrypted - it asks for password during boot, even though the OS has no password lock on it.
In addition, my WIFI is now not working!
anyone have a clue here? I REALLY want to remove the encryption on the /data partition!

I wanted to follow up here with closure. Im not exactly sure WHY what I did worked, but it did, and maybe it can help someone else.
last I left off, I had CM11 installed, but no wifi, and the partition was still encrypted. At this point, I decided to try to downgrade again to CM10.2
Now, when the tablet was booting, it was asking me for my password to decrypt so it can boot. Except now, after loading CM11 and going back to 10.2, the password wasn't working and couldn't boot. I was convinced I was bricked.
I went back into recovery, and reloaded CM11. This time, when it came up asking for my password to decrypt before booting, it worked. So something in CM11 changed the encryption on /data so that CM10.2 couldn't read it anymore.
once I was booted into CM11 (still with no wifi), I went to SETTINGS - BACKUP & RESET - FACTORY DATA RESET again. This time, it worked! Asked for my password, said are you sure, then rebooted. BOOM, /data was no longer encrypted! CM11 came up, and with the fresh /data partition, wifi even worked!
For other reasons (Netflix) Ive since gone back to 10.1, but now /data isn't encrypted, so wiping and flashing is easy and works great now.
It seems there is a bug in CM10.2 (or android) where the FACTORY DATA WIPE doesn't work with encrypted /data partitions, but CM11 was able to do that just fine.

[A510] Can't mount /data on any recovery

Hi,
I wanted to reset my 510 to a fresh 4.4.4 install. So I decided to "restore to factory settings" within the android system settings menu.
kitkat CM12 4.4.4 by shreps was working fine before, I just wanted to get rid of the data in order to give the tablet away.
now I'm stuck with a soft bricked device, it seems:
- when starting the tablet, the CM screen shows, but freezes after a while
- flashing any CM version in CWM 6..0.5 by shreps shows a "error: can't mount /data"
- wipe cache / data shows the same error
- wipe dalvik cache doesn't seem to respond in any way
- I reflashed CWM 6.0.5 using fastboot flash recovery, but to no success..
what options do I have now? can I format and remount the /data partition via ADB? do I need to go to stock?if, so, how?
Thanks for your ideas!

ok, via
fastboot -w -v
i could reformat the data partition somehow.
I still got an
E:unknown volume for path [/sd-ext]
error, but it continued and works for now.

huedrant said:
ok, via
fastboot -w -v
i could reformat the data partition somehow.
I still got an
E:unknown volume for path [/sd-ext]
error, but it continued and works for now.
Click to expand...
Click to collapse
Glad you dot it going.
I just pulled my 701 out of retirement (broke my Sony z2 screen trying to change my battery) so taking a look in here.
The data format has always been a bit twitchy, but I run the latest version of TWRP for KK. I remember bricking my original Data partition wiping it because some bozo used the wrong partition info making the original recovery for JB. Exchanged the tab.
I recall the bootloader version had to match what version of the ROM you installed (JB, KK, etc), and maybe the recovery also (can't remember). Latest TWRP for KK seems to work for me as I installed Pac Rom before I retired it. TWRP Ver 2.7.1.0
As with the "Path to ext SD", that's always been there if I recall. Just means you have to install a ROM from internal memory. Although my TWRP seems to mount it fine.
But I will say, feels like I've entered the dark ages again.