$ ./contrib/atomicrename/atomicrename -h
atomicrename creates 100 "src" files in the current directory, renames
them in random order over a single "dst" file while reading the "dst"
file concurrently in a loop.
Progress and errors are reported as they occour in addition to a summary
printed at the end. cifs and fuse filesystems are known to fail, local
filesystems and nfs seem ok.
See https://github.com/hanwen/go-fuse/issues/398 for background info.