From owner-freebsd-hackers Mon Jan 8 05:40:12 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id FAA09339 for hackers-outgoing; Mon, 8 Jan 1996 05:40:12 -0800 (PST) Received: from westhill.cdrom.com (westhill.cdrom.com [192.216.223.138]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id FAA09334 for ; Mon, 8 Jan 1996 05:40:10 -0800 (PST) From: gpalmer@westhill.cdrom.com Received: from localhost.cdrom.com (localhost.cdrom.com [127.0.0.1]) by westhill.cdrom.com (8.6.12/8.6.12) with SMTP id FAA04729 ; Mon, 8 Jan 1996 05:39:13 -0800 X-Authentication-Warning: westhill.cdrom.com: Host localhost.cdrom.com didn't use HELO protocol To: Wolfram Schneider cc: hackers@freebsd.org Subject: Re: large files In-reply-to: Your message of "Mon, 08 Jan 1996 12:15:47 +0100." <199601081115.MAA16136@caramba.cs.tu-berlin.de> Date: Mon, 08 Jan 1996 05:39:13 -0800 Message-ID: <4727.821108353@westhill.cdrom.com> Sender: owner-hackers@freebsd.org Precedence: bulk Wolfram Schneider wrote in message ID <199601081115.MAA16136@caramba.cs.tu-berlin.de>: > > 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? Because of various restrictions in the kernel, files >>2Gb aren't supported anyhow. I believe John Dyson has commited fixes to -current to increase this limit. (AFAIR, the file offset is kept as a signed int in the kernel, and the negative offsets are used to keep file metadata. If you look through the mail list archives, you may find discussions on this - I know that when we first fixed the code to support 1Tb FS's there was a discussion about file sizes). Writing to a file past the 2Gb point would have rather unpredictable results as you could probably understand, which is why the mmap() restriction is there also. Yours Gary