Subject: Re: mfs woes
To: Steven M. Bellovin <>
From: Andrew Brown <>
List: tech-kern
Date: 07/13/2004 23:34:32
On Tue, Jul 13, 2004 at 11:32:22PM -0400, Steven M. Bellovin wrote:
>In message <>, Andrew Brown writes:
>>On Tue, Jul 13, 2004 at 11:17:20PM -0400, Steven M. Bellovin wrote:
>>>In message <>, Andrew Brown writes:
>>>>write a real swap-based file system?  mfs also comes with a ~2.9
>>>>gigabyte limit (on i386, at least).  when using USE_TOPDOWN_VM.  when
>>>>you're not, it comes with a ~1.8 gigabyte limit.  regardless of how
>>>>much ram or swap you have.
>>>Given the new buffer cache architecture, I've been wondering if mfs 
>>>even makes sense these days.  Perhaps a disk partition mounted with 
>>>async would provide comparable performance?  I don't know; I haven't 
>>>tried it.  But I'm getting ready to bring up a new machine; I might 
>>>reserve a partition and see what happens.
>>mfs still makes sense as a "simple place to keep transient files that
>>you don't need from one boot to the next".  newfs'ing or rmrf'ing /tmp
>>doesn't count, imho, because it doesn't scale.
>I suspect that newfs does scale quite well to the size file system that 
>MFS can handle.

yes, but using mfs is easy whereas getting newfs to newfs a half-dozen
arbitrary small filesystems (/var/run, /cvslock, etc) at boot is not
something that you can do with one line of configuration in the
infrastructure that already exists.  :)

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