From owner-freebsd-stable@FreeBSD.ORG Wed Feb 17 18:56:44 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 00347106568F for ; Wed, 17 Feb 2010 18:56:43 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from asmtpout024.mac.com (asmtpout024.mac.com [17.148.16.99]) by mx1.freebsd.org (Postfix) with ESMTP id DF8BD8FC13 for ; Wed, 17 Feb 2010 18:56:43 +0000 (UTC) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; charset=us-ascii Received: from cswiger1.apple.com ([17.209.4.71]) by asmtp024.mac.com (Sun Java(tm) System Messaging Server 6.3-8.01 (built Dec 16 2008; 32bit)) with ESMTPSA id <0KY000E681XFFO30@asmtp024.mac.com> for freebsd-stable@freebsd.org; Wed, 17 Feb 2010 10:56:33 -0800 (PST) X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 ipscore=0 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx engine=5.0.0-0908210000 definitions=main-1002170089 From: Chuck Swiger In-reply-to: <4B7C1365.9070806@omnilan.de> Date: Wed, 17 Feb 2010 10:56:03 -0800 Message-id: <70CD649D-7659-4CE2-A16C-49B8C891CB5B@mac.com> References: <4B7C1365.9070806@omnilan.de> To: Harald Schmalzbauer X-Mailer: Apple Mail (2.1077) Cc: freebsd-stable@freebsd.org Subject: Re: best practice to watch TCP parms of established sockets X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 Feb 2010 18:56:44 -0000 Hi-- On Feb 17, 2010, at 8:03 AM, Harald Schmalzbauer wrote: > while doing some ZFS tests with RELENG_8 I recognized a mysterious performace drop after an hour uptime. > Now my first idea is to compare MSS and windows sizes before and after the performance drop. > How do I best capture them? tdpcump? It's GbE linkspeed... It seems more likely that ZFS is running into slowdowns from resource contention, memory fragmentation, etc than your network would suddenly drop out, but tcpdump -w outfile.pcap is a good method of looking.... Regards, -- -Chuck