From owner-freebsd-current Tue May 4 6:44: 3 1999 Delivered-To: freebsd-current@freebsd.org Received: from noc.demon.net (server.noc.demon.net [193.195.224.4]) by hub.freebsd.org (Postfix) with ESMTP id 6CD72154C4 for ; Tue, 4 May 1999 06:43:50 -0700 (PDT) (envelope-from fanf@demon.net) Received: by noc.demon.net; id OAA00580; Tue, 4 May 1999 14:43:49 +0100 (BST) Received: from fanf.noc.demon.net(195.11.55.83) by inside.noc.demon.net via smap (3.2) id xma000538; Tue, 4 May 99 14:43:45 +0100 Received: from fanf by fanf.noc.demon.net with local (Exim 1.73 #2) id 10efU7-0004Iv-00; Tue, 4 May 1999 14:43:43 +0100 To: current@freebsd.org From: Tony Finch Subject: Re: NFS Patch #8 for current available - new TCP fixes In-Reply-To: Message-Id: Date: Tue, 4 May 1999 14:43:43 +0100 Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Matthew Dillon wrote: > > (fanfair!) :-) > NFS attempts to realign packet buffers and trods all over the underlying > mbufs. For TCP connections, several RPC's may be present in an mbuf > chain. The realignment of one of them may destroy the others. This does > not occur with UDP because each UDP packet contains only a single rpc. > > Packet buffers may be unaligned for a number of reasons. The main reason > is due to the 14 byte MAC header on the ethernet frame. This causes the > remainder of the packet - the ip payload - to NOT be 4-byte aligned. We're planning to try replacing some Solaris web servers with FreeBSD machines in the near future. The documents are on a read-only NFS filestore connected to the web servers with CDDI. (Updates will stay on a Sun box.) Are we going to have nfs_realign problems if we use TCP in this situation or should we stick with UDP? Tony. -- f.a.n.finch dot@dotat.at fanf@demon.net Arthur: "Oh, that sounds better, have you worked out the controls?" Ford: "No, we just stopped playing with them." To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message