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From: Chris Murphy <lists@colorremedies.com>
Date: Tue, 3 Jul 2018 15:46:59 -0600
Message-ID: <CAJCQCtQVQryoycCORen=m26AtN+5__f2RnsjVP4vupSb9+0Tkw@mail.gmail.com>
Subject: Re: So, does btrfs check lowmem take days? weeks?
To: Qu Wenruo <quwenruo.btrfs@gmx.com>
Cc: Marc MERLIN <marc@merlins.org>, Chris Murphy <lists@colorremedies.com>,
        Su Yue <suy.fnst@cn.fujitsu.com>,
        Btrfs BTRFS <linux-btrfs@vger.kernel.org>
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On Tue, Jul 3, 2018 at 2:50 AM, Qu Wenruo <quwenruo.btrfs@gmx.com> wrote:
>
>
> There must be something wrong, however due to the size of the fs, and
> the complexity of extent tree, I can't tell.

Right, which is why I'm asking if any of the metadata integrity
checker mask options might reveal what's going wrong?

I guess the big issues are:
a. compile kernel with CONFIG_BTRFS_FS_CHECK_INTEGRITY=y is necessary
b. it can come with a high resource burden depending on the mask and
where the log is being written (write system logs to a different file
system for sure)
c. the granularity offered in the integrity checker might not be enough.
d. might take a while before corruptions are injected before
corruption is noticed and flagged.

So it might be pointless, no idea.


-- 
Chris Murphy