REGARDING FACTORY RESET - General Questions and Answers

Hello Everyone.
So I have an unused phone that i wanted to sell, so I Factory reset it.
But then i look at some article and found out that Factory Reset doesn't completely wipe the Data, and it could be recovered by 3rd party program.
So the question is, if I Flash my phone to a stock firmware, would all the previous data be completely erased?
I just want to make sure that my data is completely lost before selling it, since it contain lots of sensitive information.
My Phone is Sony Xperia X Performance.
Thanks in advance.

A Factory Reset wipes ALL user-data and restores system apps to the state when phone was delivered.
BTW:
Wiping and Erasing data although can sound similar refer to different things data security business.​
In short, Erase command erases or overwrites all of the data on the targeted drive, while Wipe command marks disk space as deleted / re-useable that is not being used by the Android OS ( unallocated space ). Wiped data theoreticaly can get recovered.
My recommendation: Do a Full Wipe
Code:
fastboot devices
fastboot erase userdata

Related

Internal memory not being erased?

I wanted to wipe my phone back to stock, so I did a Factory data reset in the Setting>Power menu. After it completed I connected the phone in disk drive mode, but it still had many of my old app folders in the root.
How can I get rid of these folders and go back to how I got my phone from ATT?
you can flash the RUU thats in the dev forums, it should wipe the phone.
i haven't tried to wipe this phone yet, but on my gnex, iirc, there was an option when you asked it to wipe to remove all personal data as well. i'll have to check for it on my 1x after i finish flashing the new RUU to it.
edit:
i looked again, it's in settings / storage. in there it has options to wipe saved data from the apps partition as well as the sdcard partition, and also the factory wipe.

[Q] Factory reset doesn't delete data/restore system?

Aside from the pee-stain at the bottom of the phone I did notice one thing. When you do a factory reset (and select/check that deleting userdata is okay) it does not:
• delete sdcard data
• remove user settings for apps/wifi
• restore modified system files (hosts, etc...)
• root remains as well
Is there actually a way to do a proper reset and have it restore things as it should? In line with that how do I securely erase the data if possible so in given it to a family or it ends up on some truck with Avast that the data can't be restored?
Thanks!
windraker said:
Aside from the pee-stain at the bottom of the phone I did notice one thing. When you do a factory reset (and select/check that deleting userdata is okay) it does not:
• delete sdcard data
• remove user settings for apps/wifi
• restore modified system files (hosts, etc...)
• root remains as well
Is there actually a way to do a proper reset and have it restore things as it should? In line with that how do I securely erase the data if possible so in given it to a family or it ends up on some truck with Avast that the data can't be restored?
Thanks!
Click to expand...
Click to collapse
WTF? Factory reset does not actually factory reset..? This seems like a huge bug with CM11... Especially the part about the lack of deletion in the SD card and user settings.
an_xda said:
WTF? Factory reset does not actually factory reset..? This seems like a huge bug with CM11... Especially the part about the lack of deletion in the SD card and user settings.
Click to expand...
Click to collapse
Nope. I had rooted the phone and while I think I lost root; the modified hosts file I changed (http://winhelp2002.mvps.org/hosts.htm) was still there as well as the entire SD card contents. It remembered my home wifi as well because I looked in settings and it showed my home one as "out of range"
Not sure if it's a bug or by design as I haven't tried flashing the stock image yet.
For a complete factory reset that will erase everything. Everything! You can do a factory reset from the boot loader. (Restart or power on phone and hold down the volume down button, scroll to factory reset, push power button) or from TRWP data reset, it makes you confirm and type "yes"
I reset my phone through the boot loader on accident a couple times and wanted to kick my dog.
Sent from my HTC One using XDA Free mobile app
You guys do know that factory resetting only formats the data partition excluding the /data/media directory. This is not a bug. It wouldn't need to do anything to the system partition of you don't root. And it's not able to restore the system partition without a system image and where are you going to store that? In the system partition? All user settings including apps and WiFi settings are stored on the data partition will actually be wiped unless when you log into your Google account you select restore from backup. There's no reason you would want to delete storage too when factory resetting unless you want to sell the phone and you can delete that in so many ways since it's your storage.
Sent from my TouchPad using XDA Premium 4 mobile app
cannonofcourse said:
For a complete factory reset that will erase everything. Everything! You can do a factory reset from the boot loader. (Restart or power on phone and hold down the volume down button, scroll to factory reset, push power button) or from TRWP data reset, it makes you confirm and type "yes"
I reset my phone through the boot loader on accident a couple times and wanted to kick my dog.
Sent from my HTC One using XDA Free mobile app
Click to expand...
Click to collapse
The Jack of Clubs said:
You guys do know that factory resetting only formats the data partition excluding the /data/media directory. This is not a bug. It wouldn't need to do anything to the system partition of you don't root. And it's not able to restore the system partition without a system image and where are you going to store that? In the system partition? All user settings including apps and WiFi settings are stored on the data partition will actually be wiped unless when you log into your Google account you select restore from backup. There's no reason you would want to delete storage too when factory resetting unless you want to sell the phone and you can delete that in so many ways since it's your storage.
Sent from my TouchPad using XDA Premium 4 mobile app
Click to expand...
Click to collapse
Thank you both Tried that and worked. Wanted to restore the hosts file to stock but couldn't find the original again. (didn't think to extract factory rom files on cyangen site)
The solution is in their FAQ.
so wait... if i factory reset from twrp... will my internal sd.. i.e. music.. and other files also get deleted?
abhimanyu bajaj said:
so wait... if i factory reset from twrp... will my internal sd.. i.e. music.. and other files also get deleted?
Click to expand...
Click to collapse
No.
Transmitted via Bacon
timmaaa said:
No.
Transmitted via Bacon
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and if i flash a new rom... will it be deleted?
abhimanyu bajaj said:
and if i flash a new rom... will it be deleted?
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Click to collapse
Just flashing the ROM by itself will not wipe data or internal storage, but you may encounter bugs (it's called dirty flashing). The best way to get a bug-less ROM is to clean flash which means wiping every partition. The only one that should be OK is internal so you don't have to wipe that one when clean flashing.
abhimanyu bajaj said:
and if i flash a new rom... will it be deleted?
Click to expand...
Click to collapse
No, flashing a ROM doesn't wipe user data. When flashing a new ROM it's best to wipe system, data, cache, and dalvik cache, but it isn't necessary to wipe (internal storage) user data.
Newbie XDA member
I change my phone original bootanimation and then i get No Command when i factor reset .. Nothing Happend how do just restore my (/system) /system/media bootanimation.zip ... other way to fix this thing i have pc >?

clearing dalvik cache without root.

Is it safe to clear the dalvik cache, & what exactly is cleared when I clear it? I know it can be cleared with the stock recovery, because I just helped a friend factory reset their phone who has the same phone as me (both unrooted Galaxy On5 with stock ROM) & I saw an option in the list in recovery.
tsaxda said:
Is it safe to clear the dalvik cache, & what exactly is cleared when I clear it? I know it can be cleared with the stock recovery, because I just helped a friend factory reset their phone who has the same phone as me (both unrooted Galaxy On5 with stock ROM) & I saw an option in the list in recovery.
Click to expand...
Click to collapse
Only cached data gets cleared, more specifically, cached data used by your system apps and services. This cached data will automatically be rebuilt when you reboot the device, you may or may not see a message saying "optimizing apps" while the device is rebuilding dalvik/ART cache during the boot process.
Sent from my SM-S767VL using Tapatalk
What I mean is do I lose anything important like settings/data within apps etc;. & is there any risk of my phone not booting properly? I have backed up what data I could. I've seen posts on quora, asking about different problems they had after clearing dalvik, including one who seemed to think their phone had died, but they all seem to involve rooted phones, because the solution given is always to flash another ROM/reboot to TWRP recovery. I was tempted to do it because I'm running out of space, & somebody online said there dalvik folder was 300MB.
tsaxda said:
What I mean is do I lose anything important like settings/data within apps etc;. & is there any risk of my phone not booting properly? I have backed up what data I could. I've seen posts on quora, asking about different problems they had after clearing dalvik, including one who seemed to think their phone had died, but they all seem to involve rooted phones, because the solution given is always to flash another ROM/reboot to TWRP recovery. I was tempted to do it because I'm running out of space, & somebody online said there dalvik folder was 300MB.
Click to expand...
Click to collapse
No, you won't lose anything, as I said, it is only a type of temporary data, data that is used in the background while the device is running, temporary in a similar kind of way as RAM data with the exception that RAM data doesn't necessarily persist from one reboot to the other whereas cached data does persist after reboot, unless wiped, in which case, that cached data will automatically be rebuilt exactly as it Is needed when each app loads at startup on the next reboot after the wipe.
As long as you aren't wiping the system partition or the data partition, you won't lose anything. Wiping cache is nothing to sweat over, it is a very common and necessary process when making changes to your device.
Failing to wipe when making changes to the system are what causes problems, wiping is necessary to avoid having bugs and issues caused by cached data from before the changes conflicting with the changes that you made. Wiping cache then rebooting allows the device to build the cached data the way it needs to incorporate the new changes that you made.
I called samsung to ask whether they recommended clearing it & she very sternly said "we are not clearing dalvik". It made me wonder whether she simply didn't know what dalvik is, because she asked how to spell it as though she was looking it up, or if there was some other reason.
tsaxda said:
I called samsung to ask whether they recommended clearing it & she very sternly said "we are not clearing dalvik". It made me wonder whether she simply didn't know what dalvik is, because she asked how to spell it as though she was looking it up, or if there was some other reason.
Click to expand...
Click to collapse
The option to wipe dalvik cache is not an option in stock recovery or any other stock or non-root, non-custom option. It is typically only an option if you have a custom recovery such as TWRP.
Only a developer or someone that is familiar with root and custom android software would be familiar with wiping dalvik cache. A standard employee of a manufacturer or customer support agent would not be familiar with wiping dalvik cache.
Sent from my SM-S767VL using Tapatalk
i flashed twrp and majisk yesterday but my apps was playing up so i did a delvick cache wipe and now my phone is no longer rooted and no longer has majisk do i need to install twrp and majisk again or just flash majisk again
When you reboot, bóth the Dalvik ( correct: ART ) cache and the System Cache are re-created. So no benefits at all.

How to fully wipe phone before sale (Security)

Hi all,
I know phone SD cards are generally very hard to recover once wiped, all the same, I wanted to make sure.
Wiped Data through custom recovery
Wiped Caches
Installed stock OS
Restored stock recovery
Wiped
Are these enough steps to sure the phone is secure and no data can be recovered? Thanks.
If you want to fully wipe phone before sale security, try phone data eraser tool. Such tool can help us wipe all information on phone without recovery and make it like a new one. Then there is no need to worry about data leaked. Just search it online and choose the one you like. Good luck to you.
The same zero out technique I use for hdds, with a 5 pound sledge; flatten completely and then some.
Sometimes a oxyacetylene cutting torch... a nice bonfire gets it too.
Zero chance of data recovery and fun to do
ph3n0m. said:
Hi all,
I know phone SD cards are generally very hard to recover once wiped, all the same, I wanted to make sure.
Wiped Data through custom recovery
Wiped Caches
Installed stock OS
Restored stock recovery
Wiped
Are these enough steps to sure the phone is secure and no data can be recovered? Thanks.
Click to expand...
Click to collapse
As @blackhawk mentioned: Overwriting Android's user-space several times with zeroes is fully enough. You even can do this by means of ADB.
I always just plug up to my laptop and do a: sudo fastboot -w
I've sold quite a few devices of mine over the years since Android began and t.ive always just did a format data using fastboot.
If you had some super top secret information on there maybe use some type of cleaner software program like another user here already mentioned. I've never used anything like that but I've read about them over the years online. I think a ./flash-all.sh and and not removing the fastboot -w flag is enough though, but that's just me. There are things you can purchase that will supposedly wipe it to where three is no possible way of anything ever being retrieved.
One of the most thorough ways to wipe the Android device is the factory reset.
The f actory reset deletes the complete relevant data - both the system settings data and the user settings and user data. The system applications are reset to the delivery state.
The factory reset deletes all subfolders of data (only lost+found remains) and deletes cache/dalvik-cache.

Permanently erase files/photos that have been deleted

I deleted some files from my Xiaomi phone & out of curiosity I wanted to see if they could be recovered. Unsurprisingly, I can recover the files using apps like 'Files Recovery'
However, I want to erase these files permanently. I've tried apps like 'Shreddit' that can erase empty space but the files are still showing up as recoverable.
Without having to full wipe my phone, its there a method that can remove these files permanently?
Ta
I think I've answered my own question.
It seems like 'Erase full storage' option within Shreddit did the trick. I didn't try that originally as I thought this would factory reset my phone & wipe everything.
Or you can ask help from phone data eraser software. Such software can help you wipe all personal information from your xiaomi phone without recovery. There is a lot of such software online. Most of them are not free. You can search the details online and choose the one you like. Please remember to take backup of your xiaomi phone before using such software. Hope this will be your help.
Sign out Mi account and remove Google account, boot into TWRP, get into Wipe menu and press format data, type when asked. Then flash a stock rom from MiFlash using clean all option.
A 5 pound sledge hammer provides a complete zero fill in seconds.
Works every time... for when data absolutely, positively must be deleted

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