From: Roman Mamedov <rm@romanrm.net>
To: Daniel Smedegaard Buus <danielbuus@gmail.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: Behavior after encountering bad block
Date: Fri, 19 Jun 2020 12:45:05 +0500 [thread overview]
Message-ID: <20200619124505.586f2b63@natsu> (raw)
In-Reply-To: <CAHnuAezOHbwpuVM6=bJRRtORpdHy=rVPFD+jeAQVz3xUTEsUpQ@mail.gmail.com>
On Fri, 19 Jun 2020 09:24:26 +0200
Daniel Smedegaard Buus <danielbuus@gmail.com> wrote:
> I was testing btrfs to see data checksumming behavior when
> encountering a rotten area, so I set up a loop device backed by a 1GB
> file. I filled it with a compressed file and made it rot with, e.g.,
>
> dd if=/dev/zero of=loopie bs=1k seek=800000 count=1
>
> That is, the equivalent of having data on a single block on an actual
> hard drive go bad.
Not really, because when real on-disk sectors go bad, the (properly behaving)
drive will return I/O errors, not blocks of zeroes instead.
For a closer emulation of hardware bad sectors, check out dm-dust:
https://www.kernel.org/doc/html/latest/admin-guide/device-mapper/dm-dust.html
Roman
next prev parent reply other threads:[~2020-06-19 7:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-19 7:24 Behavior after encountering bad block Daniel Smedegaard Buus
2020-06-19 7:27 ` Daniel Smedegaard Buus
2020-06-19 7:45 ` Roman Mamedov [this message]
2020-06-19 8:08 ` Daniel Smedegaard Buus
2020-06-19 9:31 ` Roman Mamedov
2020-06-19 10:06 ` Daniel Smedegaard Buus
2020-06-19 13:12 ` Remi Gauvin
2020-06-19 21:03 ` Zygo Blaxell
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