[nylug-talk] Why is hardlink necessary?

[Dan Crosta]

There are also differences in how symlinks and hardlinks (ie "real  
files") are handled by library calls. Some programs may create  
hardlinks when it's safe in order to prevent other programs from  
accidentally mishandling data with symlinks.

Additionally, I think rsync has a way to set up its behavior so that  
it keeps multiple incrementally older backups of a directory, and it  
does so with hardlinks. This prevents it having to copy data for each  
incremental backup while still preserving the full tree at its state  
in each backup. Or of course I could have just totally made that up.

- d