Date: Mon, 31 Aug 1998 15:10:21 -0500 From: "Alton, Matthew" <Matthew.Alton@anheuser-busch.com> To: "'FreeBSD-fs@FreeBSD.ORG'" <FreeBSD-fs@FreeBSD.ORG> Subject: FW: LFS/DTFS Collaboration offer (fwd) Message-ID: <31B3F0BF1C40D11192A700805FD48BF90177664F@STLABCEXG011>
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This is what is happening in my 2-pronged 3-tiered Soviet-style
5-year Plan for World Domination. I will
1) Port dtfs to FreeBSD.
2) Integrate dtfs into Greg Lehey's vinum software to achieve an
excellent filestore.
Mr. Czezatke's design is very good. I'm still studying it at this point.
> -----Original Message-----
> From: Christian Czezatke [SMTP:e9025461@student.tuwien.ac.at]
> Sent: Monday, August 31, 1998 1:29 PM
> To: Alton, Matthew
> Cc: Anton Ertl
> Subject: Re: LFS/DTFS Collaboration offer (fwd)
>
> Hi!
>
> > > I am very interested in your work on logging filesystems and am currently
> > > studying the Linux dtfs code. I am working to revitalize the 4.4BSD LFS
> > > in FreeBSD-2.2.7. I believe that our collaboration would prove mutually
> > > beneficial.
> >
> > Sorry for the late reply, I was on vacation. I have forwarded your
> > mail to Christian Czezatke, who is the one who does the hard work on
> > dtfs.
> >
> > It's good to see more efforts for collaboration between the Linux and
> > *BSD communities. However, I have discussed using the 4.4BSD LFS code
> > for Linux with Christian, and IIRC he said that the filesystem and/or
> > device interfaces are so different between Linux and 4.4BSD that it is
> > not worthwhile. So I wonder if dtfs will help you much beyond
> > understanding; but maybe you arrive at a different conclusion.
>
> Thanks for your interest in dtfs! --- As Anton has already stated, we've
> discussed using the 4.4BSD LFS code as a basis and start out with porting
> it to Linux. But after having had a look at the BSD LFS sources I
> concluded that porting BSD LFS to Linux would not be a feasible approach
> because there are some differences in the buffer cache handling.
>
> Furthermore, BSD LFS is tied to the FFS filesystem, while the filesystem
> most widely used with Linux is the ext2 FS.
>
> But I've tried to design dtfs in a way that should allow the
> implementation of various "filesystem personalities" (like ext2 or FFS) on
> top of a generic core providing logging functionality.
>
> As I'm sending out this mail I'm uploading an updated version of the dtfs
> documentation paper that also contains a description of the implementation
> of the dtfs core and a discussion of the interface between the generic
> core and the implementation of a filesystem personality on top of it.
> I think that this information could be helpful for you.
>
> You'll find this paper (version 1.6) on the dtfs homepage:
>
> http://www.complang.tuwien.ac.at/czezatke/dtfspapers.html
>
> Maybe it would be worth considering a port of the dtfs core to 4.4BSD
> since the dtfs core uses only a rather limited interface to the underlying
> buffer cache/block device drivers, but I'm not sure whether this is what
> you're heading for... (BSD is providing functionality that is not
> currently present in Linux as far as the buffer cache management is
> concerned, so porting from Linux to BSD should be easier than vice versa).
>
> One thing that could IMHO be shared with only minor modifications between
> 4.4BSD and Linux is the implementation of the cleaner.
>
> Anyhow, I think that any kind of cooperation (sharing code/ideas) is
> beneficial for both sides and I'd be glad to stay in touch with you.
>
> I could also inform you of any significant advances in the development of
> dtfs in the future, if you like.
>
> Christian
>
> --
> ----------------------------------------------------
> / Christian Czezatke <e9025461@student.tuwien.ac.at> \
> ---------------------------------------------------------
> Our continuing mission: To seek out knowldge of C, explore
> strange Un*x commands, to boldly code where no-on has manpage 4.
> - the Linux Programmer's Guide
>
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