findCopyInterruptLocation.py

# This script finds the last sector copied by GParted given an initial sector
# and an offset to the location of its copy.
#
# This is done simply by comparing sector number n to sector number
# n+<offset_of_copy>. If these match it increments n and continues.
#
#        *** WARNING: In its current form, this script is very slow! ***
#
# You may prefer to increment n by a much larger number to save time (simply
# modify numSectorsToIncrement), but this won't find the exact last copied
# sector, just one within your increment size.

import sys

partition="/dev/sda3"# <- EDIT THIS!
offset=843812864 #     <- EDIT THIS!
n=1685403600 #         <- EDIT THIS!
m=n+offset

bytesPerSector = 512
numSectorsToIncrement = 1

ntfspartition=open(partition,'rb') # Open partition

#Read data at sector n
ntfspartition.seek(n*bytesPerSector,0)
nData=ntfspartition.read(1*bytesPerSector)
print(nData)

#Read data at sector m
ntfspartition.seek(m*BytesPerSector,0)
mData=ntfspartition.read(1*BytesPerSector)

if (nData != mData):
    ntfspartition.close()
    sys.exit("Initial sectors don't match, are you sure your numbers are correct?")

print("Starting at sector " + str(m))

while (nData == mData):
    n=n+numSectorsToIncrement
    ntfspartition.seek(n*BytesPerSector)
    nData=ntfspartition.read(BytesPerSector)

    m=m+numSectorsToIncrement
    ntfspartition.seek(m*BytesPerSector)
    mData=ntfspartition.read(BytesPerSector)
    if (( m % (1024*1024*1024/512)) == 0):
        print("Offset: " + str(m/(1024*1024*1024/512)) + " GiB, current sector: " + str(m))

print("Last matching original sector is " + str(m-numSectorsToIncrement))
print("Last matching copied sector is   " + str(n-numSectorsToIncrement))

ntfspartition.close() # Close partition