From: joystick <joystick@shiftmail.org>
To: Andrea Mazzoleni <amadvance@gmail.com>
Cc: linux-raid@vger.kernel.org, linux-btrfs@vger.kernel.org
Subject: Re: [RFC v2 0/2] New RAID library supporting up to six parities
Date: Mon, 06 Jan 2014 12:59:19 +0100 [thread overview]
Message-ID: <52CA9A97.4000803@shiftmail.org> (raw)
In-Reply-To: <1389000716-3274-1-git-send-email-amadvance@gmail.com>
On 06/01/2014 10:31, Andrea Mazzoleni wrote:
> Hi,
>
> This is a port to the Linux kernel of a RAID engine that I'm currently using
> in a hobby project called SnapRAID. This engine supports up to six parities
> levels and at the same time maintains compatibility with the existing Linux
> RAID6 one.
>
This is just great Andrea,
thank you for such Epiphany present.
Just by looking at the Subjects, it seems patch number 0/1 is missing.
It might have not gotten through to the lists, or be a numbering mistake.
Does your code also support (shortcut) RMW as opposed to RCW, for all
parities?
RMW is: for a 4k write: read just nparities+1data disks, recompute
parities, write nparities+1data disks,
RCW is: "read all disks" prior to recompute parities...
Part of such RMW code should be in handle_stripe_dirtying which is not
in your patch 0/2 but that might have been in patch 0/1 which apparently
didn't get through.
See this patch by Kumar for support of RMW in raid6 (raid5 has it) which
unfortunately apparently wasn't merged up to now:
http://marc.info/?l=linux-raid&m=136624783417452&w=2
Thank you
J.
next prev parent reply other threads:[~2014-01-06 12:04 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-06 9:31 [RFC v2 0/2] New RAID library supporting up to six parities Andrea Mazzoleni
2014-01-06 9:31 ` [RFC v2 2/2] fs: btrfs: Extends btrfs/raid56 to support " Andrea Mazzoleni
2014-01-06 14:12 ` Chris Mason
2014-01-07 10:35 ` Andrea Mazzoleni
2014-01-06 11:59 ` joystick [this message]
[not found] ` <laea0q$d0g$2@ger.gmane.org>
2014-01-06 15:49 ` [RFC v2 0/2] New RAID library supporting " joystick
2014-01-06 16:08 ` Alex Elsayed
2014-01-07 11:06 ` Andrea Mazzoleni
2014-01-06 17:02 ` Phil Turmel
2014-01-06 17:27 ` David Sterba
2014-01-07 11:19 ` Andrea Mazzoleni
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