Along those lines, one thing that has bothered me is that we can't prepend files, even with modern SSDs with fancy controllers. Those controllers are jumbling the contents of a continuous disk onto different chips, and different sections on those chips.
For things like MP4 metadata that usually need to be near the beginning of a file for the MP4 to be considered streamable, it can be quite cumbersome. Being unable to expand a file from the beginning means that fancy MP4 writers write a bunch of blank space (perhaps guessing the necessary size of the metadata portion), then after the stream data is written, go back and hope that they allocated enough blank space to fit the metadata within. If the writer was wrong, either it has to put the metadata at the end of the file (preventing streaming), or has to rewrite the entire file with a bigger buffer.
Perhaps it is a wish that requires too many layers to be changed to be possible, but I like to dream.
This is already possible on Linux with certain filesystems (notably xfs and ext4), as long as the size of the data you want to prepend is an integer multiple of the filesystem block size.
For things like MP4 metadata that usually need to be near the beginning of a file for the MP4 to be considered streamable, it can be quite cumbersome. Being unable to expand a file from the beginning means that fancy MP4 writers write a bunch of blank space (perhaps guessing the necessary size of the metadata portion), then after the stream data is written, go back and hope that they allocated enough blank space to fit the metadata within. If the writer was wrong, either it has to put the metadata at the end of the file (preventing streaming), or has to rewrite the entire file with a bigger buffer.
Perhaps it is a wish that requires too many layers to be changed to be possible, but I like to dream.