Re: [RFC 0/13] extents and 48bit ext3

[Sven-Haegar Koch <haegar@sdinet.de>]

On Fri, 9 Jun 2006, Michael Poole wrote:

> Jeff Garzik writes:
>
> > Andrew Morton wrote:
> > > Ted&co have been pretty good at avoiding compatibility problems.
> >
> > Well, extents and 48bit make that track record demonstrably worse.
> >
> > Users are now forced to remember that, if they write to their
> > filesystem after using either $mmver or $korgver kernels, they are
> > locked out of using older kernels.
>
> Users are also forced to remember that, if they use certain new
> distros or programs, they are locked out of using older kernels.  They
> are forced to remember that if they have certain newer hardware, they
> are locked out of using older kernels.  They are forced to remember
> that if they use ext3 (or XFS or JFS) _at all_ they are locked out of
> using older kernels.  Why single out this particular aspect of limited
> forward compatibility to harp on so much?

I see a different problem with "ext3 + extends is not ext3 anymore" when 
the feature goes mainstream:
- user with old distri, no extends in use, no kernel support for them
- user has some kind of problem
- uses new rescue disk (aka knoppix at the time of problem) - that then
  is current stuff, and certainly uses extents - fixes problem on disk
  (may be a simple as running lilo/grub from chroot, happens often for me)
- tries to boot back into his distri -> *boom* he lost

c'ya
sven

--

The Internet treats censorship as a routing problem, and routes around it.
(John Gilmore on http://www.cygnus.com/~gnu/)
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/