But in this example the files are conceptually a flat structure. Any hierarchy would be artificial, like the common ./[first two letters]/[second two letters]/f

But in this example the files are conceptually a flat structure. Any hierarchy would be artificial, like the common ./[first two letters]/[second two letters]/filename structure. Which you can do, but it certainly doesn't make creating the above tarball any easier. Now we really need to use some kind of `find` invocation instead of a simple glob It also just extends the original question. If I have a system with 96GB RAM and terabytes of fast SSD storage, why shouldn't I be able to put tens of thousands of files in a directory and write a glob that matches half of them? I get that this was inconceivable in v6 unix, but in modern times those are entirely reasonable numbers. Heck, Windows Explorer can do that in a GUI, on a network drive. And that's a program that has been treated as essentially feature complete for nearly 30 years now, on an OS with a famously slow file system stack. Why shouldn't I be able to do the same on a linux command line?