How do I (unusualy)clean a single partition using DISKPART?

codekiddy · 21 Feb 2012

Hello and thanks for reading,

I want to achive a simple goal and need your help:
-I have 320GB external HD which has 2 partitions assigned as (X and Y),
-HD is marked as disk 1 and it's online
-partition X has some data which may not be wiped out
-while partition Y is going to be deleted and recreated.

usualy I do:
diskpart
sel dis 1
sel par Y
delete partition
cre par pri
sel par 2
format label = Y

now partition has been recreated as I wanted BUT,
part of the disk where that partition was has not been zerro-ed as it would be if we would do it like this:

diskpart
sel dis 1
clean all
cre par pri size = 153000
sel par 1
format label = X
cre par pri
sel par 2
format label = Y

now in this second example partitioin has realy been zerroed(the whole HD acctualy) because we used clean all, but the cost to achive this delux was destroing partition X as well

, and this is not wanted by my goal because I wanna keep partition X since it contains data.

My question is:
how to do recreate partiton Y so that I "zerro-it" like whole disk with clean all.
only part Y of the disk should be zerroed not part X

thanks alot.

btw: don't ask me "why do I want to do this?" I hate that

Dwarf · 21 Feb 2012

Not possible, sorry.

DiskPart Command-Line Options said:

clean
Removes any and all partition or volume formatting from the disk with focus. On master boot record (MBR) disks, only the MBR partitioning information and hidden sector information are overwritten. On GUID partition table (GPT) disks, the GPT partitioning information, including the Protective MBR, is overwritten; there is no hidden sector information.
clean all
Specifies that each and every sector on the disk is zeroed, which completely deletes all data contained on the disk.

DiskPart Command-Line Options

From the above, it is clear that these commands apply to the disk as a whole, and not to individual partitions. This is because, as part of their execution, they erase the partition information (MBR/GPT) tables. You will need to use the format command to erase a specific partition.

codekiddy · 21 Feb 2012

AFAIU-nderstand
if I use this:
format fs=NTFS

this will reformat the partition and check for disk errors on partition with focus?
but it will not zerro-it, thus, anyone can be able to recover that partition, is that correct?

thanks!

Dwarf · 21 Feb 2012

In order to securely erase a disk, the information stored on it needs to be rendered unreadable and unrecoverable. This is not as easy as it sounds, because of the phenomenon of residual magnetism (which is what data recovery specialists look for in order to recover lost data).

Basically, when you write to a disk (and that includes formatting and the clean/clean all commands as well as actual data), the existing data is not erased first. Instead, the new data is written on top. Being the most recent data stored in that location, its magnetic properties are the strongest. The HDD hardware/firmware in standard drives is designed to only recognise the stronger signal, and thus effectively ignores what has previously been written to that location. In effect, it filters out all but the strongest signal. Disk recovery specialists use special equipment that does not filter the signals, but this equipment is expensive (hence the cost, which is passed on to their customers).

There are a number of disk erasers available, and they perform their job in pretty much the same way. This is generally achieved by writing to the disk multiple times to render the residual magnetism associated with the original data sufficiently weak to be no longer viable for recovery.

Disk Wipe - Free software

Warning

Please read the instructions/help files carefully prior to use.

codekiddy · 21 Feb 2012

WOW, I didn't know that after clean all command, disk is still recoverable

thanks for explaining this! rep+

mjf · 09 Dec 2012

An old thread I know but I have a need to perform this function. That is do a rigorous clean of a single partition. "Disk Wipe" looked great but this review (by one!) thinks otherwise.

I'm thinking of:
1) Deleting all the partition files
2) Use CCleaner Tools>Drive Wiper to wipe the partition free space (all the partition in this case)
3) Do a reformat of the partition in question.

A very clunky approach but it is the only way I know at the moment.

Ztruker · 09 Dec 2012

That is not what the Disk Wipe web site says:

Disk Wipe is Free, portable Windows application for permanent volume data destruction. With Disk Wipe you can erase all disk data and prevent recovery of those data. Formatting a hard drive with regular method leaves an open possibility to recover the data back. Many companies and users who just dumped their old hard drives in rubbish had found this the hard way. Disk Wipe solves this problem efficiently, using a powerful algorithms which fill the volume with useless rubbish binary data multiple times. The possibility of recovering information from drive formatted with Disk Wipe is almost non existent.

mjf · 09 Dec 2012

Ztruker said:

That is not what the Disk Wipe web site says:

Yes I know. It would make life easy. The acid test would be to run Disk Wipe then attempt a RAW partition recovery which doesn't rely on the file system info. I may do the test but I'm feeling lazy

If you are talking data of high commercial value or of high National security then you physically destroy the HDD.

mjf · 14 Dec 2012

mjf said:

An old thread I know but I have a need to perform this function. That is do a rigorous clean of a single partition. "Disk Wipe" looked great but this review (by one!) thinks otherwise.

I'm thinking of:
1) Deleting all the partition files
2) Use CCleaner Tools>Drive Wiper to wipe the partition free space (all the partition in this case)
3) Do a reformat of the partition in question.

A very clunky approach but it is the only way I know at the moment.

Actually for those interested...I used this method and it wasn't as "clunky" as I thought. It worked like a charm. I and my son just used the one pass to delete all free space. There are more secure options DoD, NSA type multipass cleaning which can be done with CCleaner but who really needs this.