From owner-freebsd-questions Wed Dec 19 12: 7: 1 2001 Delivered-To: freebsd-questions@freebsd.org Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by hub.freebsd.org (Postfix) with ESMTP id E441837B405 for ; Wed, 19 Dec 2001 12:06:57 -0800 (PST) Received: (from dan@localhost) by dan.emsphone.com (8.11.6/8.11.6) id fBJK6nL84772; Wed, 19 Dec 2001 14:06:49 -0600 (CST) (envelope-from dan) Date: Wed, 19 Dec 2001 14:06:49 -0600 From: Dan Nelson To: Roy Sigurd Karlsbakk Cc: freebsd-questions@FreeBSD.ORG Subject: Re: increasing readahead? Message-ID: <20011219200649.GA30574@dan.emsphone.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.3.23.2i X-OS: FreeBSD 5.0-CURRENT X-message-flag: Outlook Error Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG In the last episode (Dec 19), Roy Sigurd Karlsbakk said: > I really need a LARGE readahead for my application. Does anyone know > how I can increase the current one? man setvbuf > I also need a way to pre-allocate chunks of 4 megs when I'm writing > to a file, to make the actual fragments large enough to eliminate a > large part of the actual overhead of seeking Are you sure this is your problem? FreeBSD does write clustering and allocates disk space to avoid fragmentation. -- Dan Nelson dnelson@allantgroup.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message