5 ms·
No, I mean it will store the new random data in different blocks, thus not overwriting the old blocks.
by finnw 13y ago
No, I mean it will store the new random data in different blocks, thus not overwriting the old blocks.
- dzhiurgis 13y agoEven if the whole drive is 'empty' ?
- finnw 13y agoI don't know whether a nearly-empty drive is better or worse than average. But the point is, you had a 1000-block file full of secret data and when you do > secrets.txt the file is truncated, freeing blocks 1-999 (usually block 0 is zero-filled.) If you proceed to write random data it will go to newly-allocated blocks. Then a raw read of the original blocks will expose your secret data. With dd and notrunc, the random data goes to the original blocks, overwriting your secrets.