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Date: Mon, 5 Sep 2011 17:45:37 -0500
From: Dan Nelson <dnelson@allantgroup.com>
To: Eitan Adler <lists@eitanadler.com>
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Cc: freebsd-hackers@freebsd.org, Sean Hamilton <seanhamilton@gmail.com>
Subject: Re: Recommended amount of swap
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In the last episode (Sep 05), Eitan Adler said:
> On Mon, Sep 5, 2011 at 3:48 PM, Dan Nelson <dnelson@allantgroup.com> wrote:
> > In the last episode (Sep 05), Sean Hamilton said:
> >> What is the state of the art for the recommended amount of swap in
> >> FreeBSD? Both "normal" systems with 512 MB - 8 GB of RAM, and large
> >> database systems with around 128 - 256 GB.
> 
> Keep in mind that you need at least ram = swap to get a coredump.

Not if debug.minidump is set to 1, which it is by default.  In that case,
only mapped memory gets dumped, which should ignore disk cache pages and be
a lot smaller than your RAM size.  Enabling ZFS may make your dumps bigger
unless the minidump code is smart enough to not dump the ARC.

-- 
	Dan Nelson
	dnelson@allantgroup.com