From owner-freebsd-questions@FreeBSD.ORG Sat May 14 17:11:40 2005 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 5CF9C16A4CE for ; Sat, 14 May 2005 17:11:40 +0000 (GMT) Received: from parrot.aev.net (host29-15.pool8174.interbusiness.it [81.74.15.29]) by mx1.FreeBSD.org (Postfix) with ESMTP id AA78343D2D for ; Sat, 14 May 2005 17:11:38 +0000 (GMT) (envelope-from ml.diespammer@netfence.it) Received: from soth.ventu (adsl-245-23.37-151.net24.it [151.37.23.245]) (authenticated bits=128) by parrot.aev.net (8.13.4/8.13.4) with ESMTP id j4EHFIhZ076568 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Sat, 14 May 2005 19:15:25 +0200 (CEST) (envelope-from ml.diespammer@netfence.it) Received: from [10.1.2.18] (alamar.ventu [10.1.2.18]) (authenticated bits=0) by soth.ventu (8.13.3/8.13.3) with ESMTP id j4EHAmtQ068547 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Sat, 14 May 2005 19:10:48 +0200 (CEST) (envelope-from ml.diespammer@netfence.it) Message-ID: <4286313A.3080102@netfence.it> Date: Sat, 14 May 2005 19:11:22 +0200 From: Andrea Venturoli User-Agent: Mozilla Thunderbird 1.0.2 (X11/20050502) X-Accept-Language: en-us, en MIME-Version: 1.0 To: freebsd-questions@freebsd.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.51 on 192.168.2.2 X-Scanned-By: MIMEDefang 2.51 on 10.1.2.13 Subject: NFS read-ahead? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 14 May 2005 17:11:40 -0000 Hello. I'm using an app that reads big files in small chunks. When using NFS this takes a huge amount of time, while I see user cpu roughly at 50% and system CPU again at roughly 50%. I suspect NFS is sending packets for each read (even 1 bytes) and this might generate a big overhead. Is it (or might it be so)? If yes, is there a way to set it up to perform some read-ahead? bye & Thanks av.