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Date: Mon, 9 Jan 2012 01:28:41 -0800 (PST)
From: Don Lewis <truckman@FreeBSD.org>
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Cc: arch@FreeBSD.org, adrian@FreeBSD.org, alfred@FreeBSD.org
Subject: Re: [patch] allow crash dumps to Linux swap partitions
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On  9 Jan, Nikos Vassiliadis wrote:
> On 1/9/2012 11:11 AM, Don Lewis wrote:
>> On  9 Jan, Adrian Chadd wrote:
>>> .. doesn't linux swap have some metadata somewhere?
>>
>> Darned if I know, but it doesn't seem to care about FreeBSD swap data
>> overwriting its swap partition.
> 
> Linux will not use the swap partition without the metadata. And
> these metadata are located to the start of the partition, that
> is, dumping core there will surely destroy them.

Don't we write the crash dump at the end of the partition?  I thought we
did this to make it less likely that we would overwrite the crash dump
by using swap before savecore had a chance to run.
 
> Perhaps you can add a warning in the dumpon manual page, that the
> swap metadata must be re-created after a coredump?