C# - Finding "empty" portions in a file
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I created a file with fixed size and sometimes I fill it up in diffrent positions.
What should I do if **I want to know where in that file I did not write, yet?**


One option that i tought of:

 - making Arr that contain X portions and each portion represent if that portion is complete          or not. And save it in xml file. Each time portion Y is complete, update it in that xml file.
 *X can be very big number (10,000).


I dont think its smurt and affctive solution. Any idea for aother one?