linux-btrfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Chris Murphy <lists@colorremedies.com>
To: Qu Wenruo <quwenruo.btrfs@gmx.com>
Cc: Chris Murphy <lists@colorremedies.com>,
	Michal Soltys <msoltyspl@yandex.pl>,
	Btrfs BTRFS <linux-btrfs@vger.kernel.org>
Subject: Re: many csum warning/errors on qemu guests using btrfs
Date: Wed, 29 Apr 2020 23:01:51 -0600	[thread overview]
Message-ID: <CAJCQCtTwH54CEhcGwv1S9P-i8JOgSHZFg3sKkQxAL1ppeG1cwQ@mail.gmail.com> (raw)
In-Reply-To: <cc0b6672-a65a-5c7b-d561-21cc585ead62@gmx.com>

On Wed, Apr 29, 2020 at 7:46 PM Qu Wenruo <quwenruo.btrfs@gmx.com> wrote:
>
>
>
> On 2020/4/30 上午3:21, Chris Murphy wrote:
> > On Wed, Apr 29, 2020 at 9:45 AM Michal Soltys <msoltyspl@yandex.pl> wrote:
> >>
> >> Short update:
> >>
> >> 1) turned out to not be btrfs fault in any way or form, as we recreated
> >> the same issue with ext4 while manually checksumming the files; so if
> >> anything, btrfs told us we have actual issues somewhere =)
>
> Is that related to mixing buffered write with DIO write?
>
> If so, maybe changing the qemu cache mode may help?

I thought this would only happen if the host is Btrfs? Maybe it's a
bit crazy but these days I only use Btrfs on Btrfs with cache=unsafe.
I do lots of VM force quits, never see any problems. I haven't tested
it, but I think unsafe is quite unsafe if the host crashes/power fails
while the guest is active. Performance is much better though.


-- 
Chris Murphy

  reply	other threads:[~2020-04-30  5:02 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-27 15:23 many csum warning/errors on qemu guests using btrfs Michal Soltys
2020-04-29 15:45 ` Michal Soltys
2020-04-29 19:21   ` Chris Murphy
2020-04-30  1:46     ` Qu Wenruo
2020-04-30  5:01       ` Chris Murphy [this message]
2020-04-30  7:01         ` Qu Wenruo
2020-04-30 13:12       ` Michal Soltys
2020-04-29 19:10 ` Input/output errors (unreadables files) Ferry Toth
2020-04-29 23:45   ` Qu Wenruo
2020-04-30  8:59     ` Ferry Toth

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=CAJCQCtTwH54CEhcGwv1S9P-i8JOgSHZFg3sKkQxAL1ppeG1cwQ@mail.gmail.com \
    --to=lists@colorremedies.com \
    --cc=linux-btrfs@vger.kernel.org \
    --cc=msoltyspl@yandex.pl \
    --cc=quwenruo.btrfs@gmx.com \
    /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).