linux-btrfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
To: Casey Matson-deKay <caseymdk@gmail.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: Best way to break RAID5/6?
Date: Mon, 5 Oct 2020 23:11:00 -0400	[thread overview]
Message-ID: <20201006031100.GL5890@hungrycats.org> (raw)
In-Reply-To: <CAG8D92WMf8x8YX-tMd48ZS0aEABxc2keBukwh1VeS9nryExk0A@mail.gmail.com>

On Mon, Oct 05, 2020 at 06:46:53PM -0700, Casey Matson-deKay wrote:
> Hi all,
> 
> I'm new to the community, but love the work being done here. I'm an
> embedded C developer and PCB designer, and would like to get involved
> in btrfs.
> 
> I, like many, am frustrated at the mystery of raid5/6 functionality.
> More for the learning experience than anything, I was wondering about
> the best known methods to break raid5/6 in a test setup, in order to
> understand the patterns by which it breaks, and eventually, play
> around with the kernel code to understand what's going on more in
> depth.

Welcome to btrfs!

Here's a list of known raid5 bugs with background references:

	https://lore.kernel.org/linux-btrfs/20200627030614.GW10769@hungrycats.org/

> My initial thought, taking 3 USB drives, configuring them in RAID5,
> and pulling one out during a write, seems a bit simplistic. Are there

Just pulling one out is sufficient to hit the first bug:  some reads
fail in degraded mode.  

> known raid failure modes that would be more apt for learning and
> understanding where the raid bugs lie in btrfs, and how to trigger and
> explore them?
> 
> Thank you!
> 
> Casey

      reply	other threads:[~2020-10-06  3:11 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-06  1:46 Best way to break RAID5/6? Casey Matson-deKay
2020-10-06  3:11 ` Zygo Blaxell [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201006031100.GL5890@hungrycats.org \
    --to=ce3g8jdj@umail.furryterror.org \
    --cc=caseymdk@gmail.com \
    --cc=linux-btrfs@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).