From owner-freebsd-current@freebsd.org  Wed Sep 23 15:59:37 2015
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Date: Wed, 23 Sep 2015 08:59:35 -0700
Message-ID: <CAG6CVpVvStV1pUi8WEBS0T5PaHxFk_HxGi8ch-LXU_DiheyTGw@mail.gmail.com>
Subject: Re: dumpdev in loader.conf vs rc.d/dumpon
From: Conrad Meyer <cem@FreeBSD.org>
To: Andriy Gapon <avg@freebsd.org>
Cc: FreeBSD Current <freebsd-current@freebsd.org>, freebsd-rc@freebsd.org
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On Wed, Sep 23, 2015 at 7:37 AM, Andriy Gapon <avg@freebsd.org> wrote:
>
> I have recently discovered 'dumpdev' kernel environment variable that is
> settable, for example, from loader.conf.  To me it *seems* that this variable
> has to be set to a device name / path without the leading '/dev'.

Why?

> If that's so,
> then rc.d/dumpon must prepend '/dev' when passing the value of 'dumpdev' to
> dumpon(8).

dumpon(8) opens the configured file (accessible in the normal
namespace, i.e. "/dev/ada0s1b") and uses a magical ioctl on the device
to configure it as the dump device.  This is all documented in
dumpon(8).  Additionally, dumpon.c is short and quite legible.

I don't see etc/rc.d/dumpon prepending /dev to anything.

Best,
Conrad