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Date: Tue, 24 Jun 1997 20:00:58 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199706241000.UAA15443@godzilla.zeta.org.au>
To: current@FreeBSD.ORG, kato@migmatite.eps.nagoya-u.ac.jp
Subject: Re: vm_bounce_alloc: Unmapped page
Cc: dyson@FreeBSD.ORG
Sender: owner-current@FreeBSD.ORG
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>It seems to be a cluster write related problem.  I disabled cluster
>write by:
>
>#ifdef UNION
>int	doclusterwrite = 0;
>#else
>int	doclusterwrite = 1;
>#endif

It is easier to use the sysctl for this (vfs.ffs.doclusterwrite).
This is new with Lite2.  Only ffs supports this sysctl properly.
ext2fs is the only other file system that supports clustered writes,
and its doclusterwrite variable is hidden in an ifdef tangle.

Bruce