Subject: Re: phasing out mfs; make init(8) use tmpfs?
To: None <>
From: David Young <>
List: tech-kern
Date: 02/15/2007 18:10:00
On Fri, Feb 16, 2007 at 10:44:37AM +1100, Simon Burge wrote:
> David Young wrote:
> > Is there anywhere TMPFS cannot replace MFS, and work at least as well?
> > If not, is it ok if we begin to phase MFS out?
> > 
> > I believe the only part of the system that depends on MFS is init(8).
> > If init(8) finds /dev/console missing, it creates /dev/ and runs MAKEDEV
> > in it.  I have attached a patch that makes init(8) use TMPFS, instead.
> > 
> > I will commit this within the next couple weeks unless I hear serious
> > concerns.
> I'm curious about the mfs vs tmpfs memory usage figures.  Is it
> easy for you to boot up to single user for each case and do a
> "vmstat -s | grep 'pages free'" ?

It is not easy right now, but it will be after I take Izumi and Geoff's
advice and attempt MFS after TMPFS.  I will send a new patch, and the
figures you request.

> The tmpfs case should stop the silly "you've run out of inodes"
> problem we seem to regularly see with mfs, right?

It could.  In my patch, I set a fixed number of inodes.  I guess there
is no need.


David Young             OJC Technologies      Urbana, IL * (217) 278-3933