faking free capacity of usb drive

[Cupar19]

ok guys so i know this seems a bit sketchy but i SWEAR i only want to do this as a prank on my friend, but i have filled his 32gb flash drive until it is full but i would like to have windows display it as still having 27gb left so he cant understand why files wont go onto it.

 

i understand if people who know dont want to say as this does seem quite sketchy but if anybody would that would be greatly appreciated.

[Mira Yurizaki]

You'd have to overwrite the firmware so that it reports a higher capacity than it has. Even then though, the OS will tell the drive to write more data and the drive will happily do it, but it'll start corrupting existing data rather than flat out refuse.

[Underi]

The files will go on it, but it will overwrite any existing data, thus corrupting the device.

 

Ninja'd lol

[Cupar19]

Just now, Underi said:

The files will go on it, but it will overwrite any existing data, thus corrupting the device.

 

Just now, M.Yurizaki said:

You'd have to overwrite the firmware so that it reports a higher capacity than it has. Even then though, the OS will tell the drive to write more data and the drive will happily do it, but it'll start corrupting existing data rather than flat out refuse.

ahh ok so no way to not harm the existing data?

[Cupar19]

ill try making a second small partion and hope he just doesnt look at the capacity

[Mira Yurizaki]

Just now, Cupar19 said:

ahh ok so no way to not harm the existing data?

You could modify the firmware even more to report a fake value and know how much it really has and return an error or something to the OS.

[Cupar19]

Just now, M.Yurizaki said:

You could modify the firmware even more to report a fake value and know how much it really has and return an error or something to the OS.

how would i modify the firmware?
 

[Fraser Cow]

Your practical joke isn't very practical, last thing you need is a accidentally corrupt a project he's working on and has no backup for.

[AshleyAshes]

Count down until we have a thread titled 'I screwed all the data on my friend's USB, how do I get it back!?' begins now. o____o

[TechyBen]

You want to break his USB drive? What a friend.

[Cupar19]

Just now, Fraser Cow said:

Your practical joke isn't very practical, last thing you need is a accidentally corrupt a project he's working on and has no backup for.

i already made a backup and have an exact replica drive with it on just in case that does happen

[Cupar19]

Just now, AshleyAshes said:

Count down until we have a thread titled 'I screwed all the data on my friend's USB, how do I get it back!?' begins now. o____o

 

Just now, TechyBen said:

You want to break his USB drive? What a friend.

i already made a backup and have an exact replica drive with it on just in case that does happen

[Fraser Cow]

Just now, Cupar19 said:

i already made a backup and have an exact replica drive with it on just in case that does happen

Ah, in that case go right ahead lol. A simple way to do it would be to shrink the drive and just have unallocated space.

[Mira Yurizaki]

1 minute ago, Cupar19 said:

how would i modify the firmware?

If you have to ask that question, then you probably shouldn't be doing this.

 

I mean, it involves the following:

• Finding the source code for the firmware (which is likely closed source to the vendor, so good luck)
• Knowing what kind of microcontroller is running on the USB drive
• Knowing C (most likely), and possibly assembly language for the microcontroller
• Knowing what the OS is expecting so you can return the correct thing

Among others. So it's not a very practical joke.

[Cupar19]

Just now, M.Yurizaki said:

If you have to ask that question, then you probably shouldn't be doing this.

 

I mean, it involves the following:

• Finding the source code for the firmware (which is likely closed source to the vendor, so good luck)
• Knowing what kind of microcontroller is running on the USB drive
• Knowing C (most likely), and possibly assembly language for the microcontroller
• Knowing what the OS is expecting so you can return the correct thing

Among others. So it's not a very practical joke.

ok well thx for the help il try this idea though

 

Just now, Fraser Cow said:

Ah, in that case go right ahead lol. A simple way to do it would be to shrink the drive and just have unallocated space.

 

[TechyBen]

You could see about wiring a speaker to it, so it makes a loud buzzing noise (probably need an oscillator/crystal too... ) 

 

https://www.brighthubengineering.com/consumer-appliances-electronics/68808-make-yourself-a-simple-homemade-electronic-buzzer/#imgn_3

 

Or just buy a small sparkfun/hobby craft buzzer and link it to the 5v rail of the USB stick behind a (existing or added) resistor... don't accept my electrical advice though, as you'll probably fry his PC too...

[Cupar19]

1 minute ago, TechyBen said:

You could see about wiring a speaker to it, so it makes a loud buzzing noise (probably need an oscillator/crystal too... ) 

 

https://www.brighthubengineering.com/consumer-appliances-electronics/68808-make-yourself-a-simple-homemade-electronic-buzzer/#imgn_3

 

Or just buy a small sparkfun/hobby craft buzzer and link it to the 5v rail of the USB stick behind a (existing or added) resistor... don't accept my electrical advice though, as you'll probably fry his PC too...

ohh cool idea ill try that on mine but doesnt help my plan

[Pyramiden]

Why not just format the drive and create a 27GB partition and leave the rest as unallocated space?...