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Date: Tue, 9 Jan 1996 01:43:59 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199601081443.BAA00924@godzilla.zeta.org.au>
To: hackers@FreeBSD.org, wosch@cs.tu-berlin.de
Subject: Re: large files
Sender: owner-hackers@FreeBSD.org
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>On FreeBSD 2.0 I can mmap only file less than 2GB (SSIZE_MAX alias
>INT_MAX). On FreeBSD 2.1 I can't write(2) to files larger than 2GB
>(and don't test if mmap works with 2GB files).

>Why?

Files larger than 2GB didn't work in in FreeBSD or previous versions. 
2.1 apparently enforces the limit better.

There's some chance that large files work in -current.  The lseek
method allows creation of a 32GB file on a 32MB file system.  Your
example works more or less as expected: mmapping slightly less than
4GB doesn't work, but mapping a window of size (file_size % 2GB).
for file sizes of slightly less than 2G, 4GB, 6GB and 8GB.

Bruce