From owner-freebsd-hackers  Sat Oct 21 15:40:26 1995
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Date: Sat, 21 Oct 1995 15:40:24 -0700
From: Jeffrey Hsu <hsu>
Message-Id: <199510212240.PAA15552@freefall.freebsd.org>
To: boot@waterw.com
Subject: Re: > 2 gig filesystems
Cc: hackers@freebsd.org
Sender: owner-hackers@freebsd.org
Precedence: bulk

This wouldn't happen to formerly be a 1.1 filesystem, would it?  I used
to have the same problem, then I gave up and newfs'ed a 2.0 fs and
moved everything over.

In any case, -current has some lseek patches which may fix your problem
(didn't solve mine).