With my upgrade to the GS4, I now have a Bionic that is gathering dust. If I were to sell it, is there a way I can completely erase it, so that sensitive data cannot be recovered down the road? I.E. something more robust than a plain FDR?
Thank you!
I've never heard of someone recovering info after a factory data reset... I'm sure it's probably possible, given enough time/desire.
If is that important you could always write over sensitive info with fake/junk before wiping.
There may be encryption programs to do this on phone, but not familiar with one.
Just my take on it.
Just a general example of zero-ing out a disk. Rewrites and fills the disk with zeros to make sure all previous data is overwritten.
dd if=/dev/zero of=/dev/sda bs=1M
You could mount your internal and external sd cards and zero them out, just point of= to the partition number, ie of=/dev/sdb1
Not too sure about zero-ing the app data partition. Should be possible, and no problem since it's rebuilt on a rom flash.. I just haven't dabbled there myself.
For security reasons, you should instead fill the partitions with /dev/urandom but this takes longer, and is usually only for the extreme paranoid/experts
ps. I've read that this may cause quite a lot of write cycles on the storage, which kills flash memory.
sent from a Bionic
Related
I reformatted the Internal Memory (4GB) with the trialversion of CnetX Flash Format, using FAT32 with 16k clustersize (as opposed to 4k clustersize).
Starting large applications from the Internal Storage is now 25% faster. TT7 took 17 seconds from start to 100% route calculation, after formatting it takes 13 seconds.
Remember to backup internal storage first.
Format the internal storage is a good thing to do from time to time, i defrag it with Perfect Disk
omaga said:
Format the internal storage is a good thing to do from time to time, i defrag it with Perfect Disk
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Perfectdisk - sounds interesting...where did you get that from?
neilsupermac999 said:
Perfectdisk - sounds interesting...where did you get that from?
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http://tinyurl.com/awwxn3
JonInAtl said:
http://tinyurl.com/awwxn3
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The reason for asking the question is that googling 'perfect disk windows mobile' doesnt bring up anything particularly obvious in relation to defragging handset storage.
I'll refrain from passing any more comments on your post..but thank you...no...really.
omaga said:
Format the internal storage is a good thing to do from time to time, i defrag it with Perfect Disk
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Defrag a Flash based memory? This is absolute unnecessary:
Flash memory isn't accessed by a single read/write head. So it doesn't need its contained files to be made contiguous and moved closer together to speed access. This means that there is an unexpected - by me at any rate - benefit to flash memory compared to hard drives. You don't need to do so much house-keeping.
You may have applications that assume or require files in flash memory to be contiguous. In that case defragging would be a good idea. But wait, there is a problem. Flash memory only supports a finite number of writes and defraging involves a lot of writing. So by defragging flash you are shortening its working life.
neilsupermac999 said:
The reason for asking the question is that googling 'perfect disk windows mobile' doesnt bring up anything particularly obvious in relation to defragging handset storage.
I'll refrain from passing any more comments on your post..but thank you...no...really.
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I had the same results but after going ahead and looking at the demo version it's still not clear how Perfect Disk works with the Diamond internal storage.
--Never mind--
Figured it out, forgot I could use Settings/USB to PC to set device as a "removable disk". Works fine.
I have done that before and yes it does seem to speed up the phone
MarcLandis said:
Defrag a Flash based memory? This is absolute unnecessary:
Flash memory only supports a finite number of writes and defraging involves a lot of writing. So by defragging flash you are shortening its working life.
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So you would recommend not using the built in capability to use the Diamond memory as a removable disk or is there something in the defrag process that is substantially different than user read/writes related to working life?
Interesting that your post is a direct quote from a Nov 05 Techworld posting (for which you may have been the author). Here is a more contemporary and empirical exercise on the subject of fragmented flash memories:
http://www.lagom.nl/misc/flash_fragmentation.html
Having said all that, I didn't expect much just thought there might be some overhead cleanup, and I didn't worry over shortening the life of the memory, but could be convinced otherwise.
d-e-l-e-t-e
Reformatting with bigger cluster size will give a bit better performance at the cost of space. You wont notice much unless there's loads of small files though. A 1 byte file will still take up the same amount of size on the disk as the cluster size. If a file is 1 byte larger then the cluster size it will take up the same amount of space as 2x the cluster size. In other words it will always round up.
Defrag a flash unit however I don't think is wise. I red that you should not defrag SSD drives for pc as it may affect the life span on them, and it makes no sense defraging them anyway since they are not accessed like a harddrive.
Was wondering if there is a tool available to perform scan on our sdcard and also defragement it. Or maybe a command from the console to also perform this task just like on a window OS.
Sent from my FIH-FB0 using xda premium
wesleyel said:
Was wondering if there is a tool available to perform scan on our sdcard and also defragement it. Or maybe a command from the console to also perform this task just like on a window OS.
Sent from my FIH-FB0 using xda premium
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From my knowledge of Linux this is taken care of by the system on boot. Defrag, scandisc would preferred at system or swap partion if used for a longer time. Depends on file system more than windows applieable in this case. Please correct me on this..
My dog sent this while a I took a leak...
Not sure about scandisk utilities, but defrag is only necessary for conventional hard drives that contain an actual spinning disk. The reason for this is that on a spinning drive, fragmented files are scattered across multiple physical locations on the disk. This is not a concern for solid state drives, including both built-in storage and SD cards. With solid-state memory, the physical location of data is irrelevant.
In fact, defragmenting solid-state memory is actually detrimental to the hardware. Each "cell" of the chip can only survive a few hundred of thousand delete/write cycles before it fails. This is typically not a concern as A) this is usually far more than would happen during the expected life of the device itself and B) low-level software performs "wear-leveling" ensuring that some cells don't get written to excessively while others remain unused and C) this low-level software is also able to detect bad cells and flag so they do not get used, in a way that is completely transparent to the end user. The reason defragmenting is bad for solid-state chips is that it involves many delete/write operations which slowly degrade the chip, but which ultimately serve no greater purpose.
Thanks for clearifying this.
My dog sent this while a I took a leak...
Zfwaeld said:
Not sure about scandisk utilities, but defrag is only necessary for conventional hard drives that contain an actual spinning disk. The reason for this is that on a spinning drive, fragmented files are scattered across multiple physical locations on the disk. This is not a concern for solid state drives, including both built-in storage and SD cards. With solid-state memory, the physical location of data is irrelevant.
In fact, defragmenting solid-state memory is actually detrimental to the hardware. Each "cell" of the chip can only survive a few hundred of thousand delete/write cycles before it fails. This is typically not a concern as A) this is usually far more than would happen during the expected life of the device itself and B) low-level software performs "wear-leveling" ensuring that some cells don't get written to excessively while others remain unused and C) this low-level software is also able to detect bad cells and flag so they do not get used, in a way that is completely transparent to the end user. The reason defragmenting is bad for solid-state chips is that it involves many delete/write operations which slowly degrade the chip, but which ultimately serve no greater purpose.
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Wow I just got educated. Thanks a ton bro...
Sent from my FIH-FB0 using xda premium
wesleyel said:
Was wondering if there is a tool available to perform scan on our sdcard and also defragement it. Or maybe a command from the console to also perform this task just like on a window OS.
Sent from my FIH-FB0 using xda premium
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There is no need to defragment as told already above. But you can Consolidate free space to make a large pool of free space and yes Consolidating free space increases "write" speed if memory is low because to writing to several small location takes more time than writing to a continuous memory block... use MyDefrag free software to Consolidate space.
But, when it is damage SD, dont knwo why... becasue i didnt touch the ****ing cell phone.. it is not a "scandisk" command from system or any app could make it? I cant find nothing.. must I take it out and do it under windows???
thanks.
Any clues why?
As said, Samsung Galaxy S i9000 without any modifications apart from an official 2.2 to 2.3 Android upgrade from Samsung.
The phone got dropped before it was noticed, but not particularly hard.
The SD card was empty apart from two (empty) directories:
.andriod_secure
LOST.DIR
I ran RECUVA and it ONLY found 6 MP3 files, but none of the important movieclips of the kids in Eurodisney... The 6 MP3 files were in excellent shape, there were no other files found either in good or bad shape.
It's the wife's phone. She has older backups, but the backup after the Disney visit didn't work and she thought, meh, I'll try again in a while. Bad decision...
- What happened here?
- Did the phone actively wipe the card somehow?
- Can dropping a phone wipe an SD card (or can you think of any situation where this could even be remotely possible, like while writing to it)?
- Anything else I should try?
On a more technical level: how does an SD card work? Magnetically stored info on a platter of an old fashioned harddrive stays there after deleting the TOC (or whachamacallit, I thought this is what happens if you delete/format it). But the bits on an SD card also stay where they are after a simple 'delete' or 'format' action, right? So does that give an indication what happened, since I could only recover 35MB out of ~6GB used data? (8GB class 4 Sandisk)
As I understand it, electricity is used to write flash memory, but once it is in there, it stays in there.
(BTW, I worked in a company using flash memory in a device that would sometimes have an empty battery or where the PCB would even literally drown. The lack of battery power was clearly visible in a block of data, it started out normally, but would end in FF's (as seen with UltraEdit), a clear sign that this block had been wiped (all bytes set to FF), but while writing, it failed to finish writing the entire block. The drowning victims, we would remove the chip and place it on an external-read-out board and still be able to salvage data, even with half rotted pins on the chip :raz:. )
You probably came across this question before, and if you have htc one you will probably have the same problem..
I looked into a lot of threads but none found the answer.
When i go to storage, "other" is occupying 7gb of space.. That's pretty insane considering from other threads I saw it's only system or software os space and there is no way to look into it and find out what it is. I have 1 picture below and on the far left it says I have 25gb of storage.. Completely ignores those 7 other go cause I have a 32gb phone.
Some say it may be backup information, stuff you deleted and it stays there so if you need it back you can access it.
Is there any way to fix it? Without whiping everything cause that's proven to only decreases the size a bit. It's only getting bigger, I hope I can get rid of a big part of it so I can have more space. I'm not rooted.
Andromon 01 said:
You probably came across this question before, and if you have htc one you will probably have the same problem..
I looked into a lot of threads but none found the answer.
When i go to storage, "other" is occupying 7gb of space.. That's pretty insane considering from other threads I saw it's only system or software os space and there is no way to look into it and find out what it is. I have 1 picture below and on the far left it says I have 25gb of storage.. Completely ignores those 7 other go cause I have a 32gb phone.
Some say it may be backup information, stuff you deleted and it stays there so if you need it back you can access it.
Is there any way to fix it? Without whiping everything cause that's proven to only decreases the size a bit. It's only getting bigger, I hope I can get rid of a big part of it so I can have more space. I'm not rooted.
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Ok so your phone have a memory chip of 32gb.
Its divided in 37 different partitions.
Partitions 1 to 34 are reserved for the firmware (bootloader, secondary bootloader, recovery, radio, kernel, mfg, misc, drivers and some more).
partition 35 is the system
partition 36 is the cache
partition 37 is your user data partition and is composed of the remained space.
Available user memory is +/- 25gb for everyone.
That's not good.. So there's no way I can make that size smaller?
I want to recover photos and videos from my device, I made factory reset from recovery so all the data are lost now and I want to recover them and the device is not rooted, is there and way to do that??
its my first holiday photos and videos with my son
You shouldn't have done a reset if you wanted to try and recover data... I write would them off and move on. In the future back up critical data at least twice on electronically isolated hdds.
Yeah, @blackhawk is right. You need to backup beforehand. Doing a factory reset was the end of it, mostly.
Sadly you don't have low-level access to the eMMC memory chip, even with root is hard to get it down right, so there is no recovery of lost data available to you.
If that data was extremely precious to you your only option would be a data recovery center (which would try to read the data pages right off the chip itself externaly) but that means you should not use the device in order to ovoid overwrites of the pages and trim triggers.
ban.codrut said:
Yeah, @blackhawk is right. You need to backup beforehand. Doing a factory reset was the end of it, mostly.
Sadly you don't have low-level access to the eMMC memory chip, even with root is hard to get it down right, so there is no recovery of lost data available to you.
If that data was extremely precious to you your only option would be a data recovery center (which would try to read the data pages right off the chip itself externaly) but that means you should not use the device in order to ovoid overwrites of the pages and trim triggers.
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People smash their screens or otherwise total their phones too but they are in a better position if they're willing to go to extremes.
Something like this:
https://flashfixers.com/recover-data-dead-phone-chip-off-data-recovery/
With an intact phone the cost should be lower but as you pointed out still very problematic.
The file system was destroyed by the reset so any recovered data be bits and pieces that are juxtaposed like a huge broken jigsaw puzzle.
Jpegs be intact but all related metadata like pic #, time stamps etc be lost... if they haven't already been overwritten.
I've used recovery software and what you recover is a huge brain numbing mess. Even sorting out a 100 images from a flashcard is a chore let alone a whole phone worth of data.