> > i don't think of any usage for which inclusion of "nfs" is useful.
> 
> I can! Any tool which wants to know what io stat names are available. 

for example?

> I think a better thing to do is rename the variable to "iostatnames". Then 
> it makes a lot of sense to include nfs in the list of all iostat-providing 
> sources.

for what is it useful, in addition to statistics themselves,
which include those names?

YAMAMOTO Takashi