never say never [was Re: ZFS]

[Matt Emmerton]

[ moving to -chat since we're on a tangent here ]

> On Wed, Sep 15, 2004 at 06:03:22PM +0100, Matthew Seaman wrote:
> > On Wed, Sep 15, 2004 at 05:43:38PM +0200, Wilko Bulte wrote:
> > > On Wed, Sep 15, 2004 at 05:26:39PM +0200, Andrea Campi wrote..
> > > > On Wed, Sep 15, 2004 at 10:59:36AM -0500, Sam wrote:
> > > > > Call me crazy, but does anyone else see this as hooey?  2^64 512B
> > > > > sectors is 8192 zettabytes (zetta, exa, peta, tera, ...).
> > > > [...]
> > > > > Crappy marketing articles.
> > > >
> > > > This one's good though. fortune(6) worthy, I mean:
> > > >
> > > > Populating 128-bit file systems would exceed the quantum limits of
> > > > earth-based storage. You couldn't fill a 128-bit storage pool
without
> > > > boiling the oceans.
> > >
> > > Hmmmm... that explains the global warming then...
> >
> > I once calculated that there were sufficient IPv6 addresses (another
> > 128 bit quantity) to provide a distinct address for every cluster of
> > about 10^12 atoms within planet Earth.  10^12 atoms sounds like quite
> > a lot, but it is much smaller than a typical bacterium and a hell of a
> > lot smaller than any transistor ever manufactured: even if you
> > converted the entire planet into a data storage system, you wouldn't
> > have enough matter to build a filesystem that big, let alone power
> > supplies, cabling, support structures etc.
>
> Be ware...
>
>   Jules Verne was called crazy when he saw men would walk on the moon
>   sometime.
>
>   Leonardo da Vinci was laughed at when he envisioned people flying like
>   birds.
>
> We people had things wrong in the past when we held things for impossible.
>
> We may not be around to witness storing over 2^128 bytes of information
> but your words sound like NEVER and I think that's a scary word.

I agree totally.

I work in a large database shop, and recently we decided that we wanted to
build a smaller version of one of our large test systems -- a 64-way machine
a 20TB database.  (Sorry, not running FreeBSD.  If only they'd pay me to
make it happen.)

Rather than rebuild a half-size (10 TB) database from scratch on the smaller
system (which would take at least a week with somewhat constant attention),
we opted for the simple approach which took less than a day.

What is the simple approach, you ask?  We installed 8 Gbit ethernet adapters
on each machine, hooked them together to create suitably large private
network, and just did dd copies of the raw devices over the network.

Now, who would have ever thought that this would be possible 5 years ago?
10 years ago?  15 years ago?

Never say never.

--
Matt Emmerton