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Date: Thu, 27 May 2010 18:30:07 -1000
From: Clifton Royston <cliftonr@lava.net>
To: Dave Hayes <dave@jetcafe.org>
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Cc: freebsd-stable@freebsd.org
Subject: Re: Locking a file backed mdconfig into memory
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On Thu, May 27, 2010 at 04:48:42PM -0700, Dave Hayes wrote:
> On FreeBSD 7.3-STABLE I'm mounting a DVD and doing something like
> this:
>  
>   mdconfig -a -t vnode -o reserve -o readonly -f /dvd/file
> 
> so that /dvd/file becomes the backing storage for my memory
> disk. 

It sounds like what you really want is to load the contents of the
specified file as a memory system?  That's not part of mdconfig's
repertoire, to the best of my recollection.  

If that's what you want, you need to use a different tool; the purpose
of mdconfig is to provide scratch disk.  The backing store is to
specify a region its contents can be swapped out to if the system is
under memory pressure (which certainly won't work with a DVD)

  -- Clifton

-- 
    Clifton Royston  --  cliftonr@iandicomputing.com / cliftonr@lava.net
       President  - I and I Computing * http://www.iandicomputing.com/
 Custom programming, network design, systems and network consulting services