raid5 - again

raid5 - again

[Roy Sigurd Karlsbakk]

hi

It's been some two years since I read about the becoming of raid5 etc i=
n btrfs. Since the code is available in linux, why isn't this already i=
n btrfs? Is Oracle holding back?

--=20
Vennlige hilsener / Best regards

roy
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Re: raid5 - again

[Marcin Kuk]

2011/2/19 Roy Sigurd Karlsbakk <roy@karlsbakk.net>:
> hi
>
> It's been some two years since I read about the becoming of raid5 etc in btrfs. Since the code is available in linux,

Code of what? Raid5? Raid5 is some functionality that can't be easly
ported to another project with different blocks management and
structure.

> why isn't this already in btrfs? Is Oracle holding back?

IMO Raid5 in btrfs should be implemented from scratch.

[Sorry if I didn't understand you]

Regards,
Marcin Kuk

Re: raid5 - again

[Chris Samuel]

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On Sun, 20 Feb 2011 08:48:24 AM Marcin Kuk wrote:

> IMO Raid5 in btrfs should be implemented from scratch.

I believe Roy was referring to the development work that
others were doing on raid5 in btrfs and was residing outside
of Chris's trees.

However, as Hugo has pointed out, Chris is busy with getting
a functional btrfsck going.

All the best,
Chris
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 Chris Samuel  :  http://www.csamuel.org/  :  Melbourne, VIC

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Re: raid5 - again

[Hugo Mills]

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On Sat, Feb 19, 2011 at 10:11:30PM +0100, Roy Sigurd Karlsbakk wrote:
> It's been some two years since I read about the becoming of raid5
> etc in btrfs. Since the code is available in linux, why isn't this
> already in btrfs? Is Oracle holding back?

   It's about resourcing and stability. Oracle only employ one person
(AFAIK) on btrfs -- Chris Mason. He does a sterling job of maintaining
and developing the filesystem, but there is only one of him.

   Since well before December, he's been working on a functional fsck,
trying to get it to a state where it won't demolish your filesystem
even more than it already is. This has left the work to integrate the
RAID-5/6 patches behind. He's also been working hard on fixing a great
many other stability issues as they're reported, and integrating
patches from other developers.

   I believe that RAID-5/6 is the next major piece of work that Chris
is intending to integrate, once fsck is ready. However, stability is
better than features at this point. I don't see any commercial benefit
in preventing the integration and deployment of the RAID-5/6 patches,
but simply that there's other things that are more important. Please
be patient.

   Hugo.

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