Whenever I delete a large file -- "large" as in 2GB or more -- the whole
system slows waaaaaaaaaaaaay down for a minute or so. It runs so slowly
that it's about 99% unresponsive. The larger the file, the longer the
slowdown lasts. If I delete several large files all at once, then the
slowdown lasts even longer.

What happens when I delete a big file that causes such an intense, if
somewhat short-term, resource demand?

# uname -a
SunOS wwm1 5.10 Generic_118822-25 sun4u sparc SUNW,Sun-Blade-100