Teach mdmfs about tmpfs and use tmpfs in rc scripts

[Ian Lepore]

On Fri, 2014-03-07 at 12:52 +0800, Jia-Shiun Li wrote:
> On Fri, Mar 7, 2014 at 7:26 AM, Ian Lepore <ian at freebsd.org> wrote:
> >
> > Thoughts?
> >
> 
> Is it ok to default mdmfs to tmpfs behavior? Not sure if anyone would
> like to have explicit allocation e.g. failing early on insufficient memory,
> rather than failing on write. If so then at least 'md' should be in the
> options in addition to 'auto' and 'tmpfs' when both md and tmpfs are
> available from kernel.
> 

I'm not sure what you mean.  If the device on the command line is md the
program behaves as it always has.  If you ask for 'auto' you get the
"best" memory filesystem available for some definition of "best".  If
you don't trust someone else's definition of best (like you need failure
at allocation time) then you choose the one that behaves the way you
like.

-- Ian