Re: Plans for 1.8+ (2.0?)

["Dmitri Nikulin" <dnikulin@xxxxxxxxx>]

On 2/1/07, ricardo <ricardo@igotbsd.org> wrote:
> On Wed, 31 Jan 2007 21:35:42 -0500 (EST)
> "Justin C. Sherrill" <justin@shiningsilence.com> wrote:
>
> > On Wed, January 31, 2007 3:18 pm, Matthew Dillon wrote:
> > >
> >
> > >     I am seriously considering our options with regards to ZFS or a
> > >     ZFS-like filesystem.  We clearly need something to replace UFS,
> > >     but I am a bit worried that porting ZFS would be as much work
> > >     as simply designing a new filesystem from scratch.
> >
> > One of the reasons people are so excited about ZFS is because it
> > solves the problem of managing space.  Disk management is and has
> > always been a pain in the rear, and ZFS goes a long way toward
> > reducing that.
> >
> > While constructing a new filesystem will help your goals, it will also
> > mean that DragonFly users miss out on having all the other advantages
> > that come with ZFS.  Put another way, we're going to lose planned
> > functionality.
>
>   You're implying that ZFS=God, in other words, you're implying that
> there could be no better FS that ZFS. A very obnoxious statement!

That's not his point. He means that ZFS, while very good at what it
is, would not be optimal for transparent clustering. And a file system
which is designed for clustering won't necessarily be as good as ZFS
on single machines. Either way, some use cases becomes sub-optimal,
and it's a choice of what's more important to do first.

ZFS is optimized all the way down to avoiding byte swapping with a
simple but adequate "endian adaptiveness" technique, and being as new
as it is, it still has a few years worth of optimization potential.
It's definitely not going to perform as well on DragonFly as it does
on Solaris for a long time, but it could still be better than UFS by
design alone. Any optimization over that is just a bonus.

On the other hand, I'm not convinced there's a need to make a new
filesystem just for clustering, not just yet anyway. How about 9P?
It's not like clustering is a brand new problem, it's had decades of
research applied and there is no shortage of work to reference until
it's practical to attempt to do better.

---
Dmitri Nikulin

Centre for Synchrotron Science
Monash University
Victoria 3800, Australia