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Date: Fri, 17 Sep 2004 12:29:51 -0400 (EDT)
From: Robert Watson <rwatson@FreeBSD.org>
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To: Brian Fundakowski Feldman <green@FreeBSD.org>
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cc: Giorgos Keramidas <keramida@FreeBSD.org>
cc: Ceri Davies <ceri@submonkey.net>
Subject: Re: cvs commit: src/sys/sys mdioctl.h src/sys/dev/md md.c
	src/sbin/mdconfig Makefile mdconfig.8 mdconfig.c
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On Fri, 17 Sep 2004, Brian Fundakowski Feldman wrote:

> On Fri, Sep 17, 2004 at 11:53:40AM -0400, Robert Watson wrote:
> > On Fri, 17 Sep 2004, Ceri Davies wrote:
> > 
> > > > +> I think most of us were already jealous enough by seeing the first post :-P
> > > > +> (Thanks for the extra md coolness these commits made possible :-))
> > > > 
> > > > Jealous about what?:) You know, that you can setup 15TB of md(4) swap-backed
> > > > device on 512MB swap partition, right?
> > > 
> > > What happens if you try to fill them?
> > 
> > Bewm.
> 
> Doesn't that have mostly to do with vm_page_grab() and sf_buf_alloc()
> and vm_pager_get_pages() not having any sort of error handling?  I guess
> that vm_pager_alloc() is also missing it.... 

There are probably numerous sorts of errors, not least that once you fill
your swap space, you're going to be out of swap, and file systems are
written to assume that disks don't run out of space after declaring they
have the space (i.e., that they really are disks).

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert@fledge.watson.org      Principal Research Scientist, McAfee Research