> It's obviously information that's stored _somewhere_.
Yes, but it is a pre-allocated somewhere (part of the MFT) so no extra space is taken until a directory grows really huge or there is enough stuff using the MFT that it needs to be expanded. IIRC each directory will be taking a 1Kbyte block in the MFT in an experiment like this, plus a bit for the directory they are in needing to consume more blocks to describe them.
Similar to creating lots of very short files might not initially take any space on common Linux filesystems, as they use nothing more than the pre-allocated inodes.
Yes, but it is a pre-allocated somewhere (part of the MFT) so no extra space is taken until a directory grows really huge or there is enough stuff using the MFT that it needs to be expanded. IIRC each directory will be taking a 1Kbyte block in the MFT in an experiment like this, plus a bit for the directory they are in needing to consume more blocks to describe them.
Similar to creating lots of very short files might not initially take any space on common Linux filesystems, as they use nothing more than the pre-allocated inodes.