> > The flash will then contain _random_ data in the non-used blocks. > > That is not a problem, right? > > Nope. So long as the previously written (random) data on the card > doesn't contain anything security sensitive. I understood. > > Although I have very small amount of files in my 4G image, > > I see that the image has almost no zero-filled blocks. > > Is that normal for ext4? > > It depends on how you created the image. I create the image like this: dd if=/dev/zero of=a.img bs=4096 count=1048576 mkfs.ext4 a.img mount -t ext4 -o loop a.img /mnt cp -a /foo/* /mnt/ umount /mnt > > Can zerofree.c recognize them as non-used blocks? > > Yes, it uses the block allocation bitmaps to understand what is used > and non-used. Great. Thanks Round -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
