From: Neal Gompa <ngompa13@gmail.com>
To: David Sterba <dsterba@suse.com>
Cc: Btrfs BTRFS <linux-btrfs@vger.kernel.org>
Subject: Re: [PATCH v3 0/4] RAID1 with 3- and 4- copies
Date: Fri, 1 Nov 2019 10:54:45 -0400 [thread overview]
Message-ID: <CAEg-Je_oNz5BtpRAF3fzfX1G-Dhh7yjpshyy47NwLaREWv0wBQ@mail.gmail.com> (raw)
In-Reply-To: <cover.1572534591.git.dsterba@suse.com>
On Thu, Oct 31, 2019 at 11:17 AM David Sterba <dsterba@suse.com> wrote:
>
> Here it goes again, RAID1 with 3- and 4- copies. I found the bug that stopped
> it from inclusion last time, it was in the test itself, so the kernel code is
> effectively unchanged.
>
> So, with 1 or 2 missing devices, replace by device id works. There's one
> annoying thing but not new: regarding replace of a missing device, some
> extra single/dup block groups are created during the replace process.
> Example below. This can happen on plain raid1 with degraded read-write
> mount as well.
>
> Now what's the merge target.
>
> The patches almost made it to 5.3, the changes build on existing code so the
> actual addition of new profiles is namely in the definitions and additional
> cases. So it should be safe.
>
> I'm for adding it to 5.5 queue, though we're at rc5 and this can be seen as a
> late time for a feature. The user benefits are noticeable, raid1c3 can replace
> raid6 of metadata which is the most problematic part and much more complicated
> to fix (write ahead journal or something like that). The feedback regarding the
> plain 3-copy as a replacement was positive, on IRC and there are mails about
> that too.
>
What's the reasoning for not submitting this for 5.4? I think the
improvements here are definitely worth pulling into the 5.4 kernel
release...
--
真実はいつも一つ！/ Always, there's only one truth!
next prev parent reply other threads:[~2019-11-01 14:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-31 15:13 [PATCH v3 0/4] RAID1 with 3- and 4- copies David Sterba
2019-10-31 15:13 ` [PATCH v2 1/4] btrfs: add support for 3-copy replication (raid1c3) David Sterba
2019-10-31 15:13 ` [PATCH v2 2/4] btrfs: add support for 4-copy replication (raid1c4) David Sterba
2019-10-31 15:13 ` [PATCH v2 3/4] btrfs: add incompat for raid1 with 3, 4 copies David Sterba
2019-10-31 15:13 ` [PATCH v2 4/4] btrfs: drop incompat bit for raid1c34 after last block group is gone David Sterba
2019-10-31 18:43 ` [PATCH] btrfs-progs: add support for raid1c3 and raid1c4 David Sterba
2019-10-31 18:44 ` [PATCH v3 0/4] RAID1 with 3- and 4- copies David Sterba
2019-11-01 14:54 ` Neal Gompa [this message]
2019-11-01 15:09 ` David Sterba
2019-11-03 0:35 ` waxhead
2019-11-04 13:40 ` David Sterba
2019-11-14 5:13 ` Zygo Blaxell
2019-11-15 10:28 ` David Sterba
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=CAEg-Je_oNz5BtpRAF3fzfX1G-Dhh7yjpshyy47NwLaREWv0wBQ@mail.gmail.com \
--to=ngompa13@gmail.com \
--cc=dsterba@suse.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).