From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 9 Aug 2001 10:26:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 9 Aug 2001 10:26:02 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.101]:6790 "EHLO e1.ny.us.ibm.com") by vger.kernel.org with ESMTP id ; Thu, 9 Aug 2001 10:25:51 -0400 Importance: Normal Subject: Re: Swapping for diskless nodes To: "Dirk W. Steinberg" Cc: Ingo Oeser , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Alan Cox X-Mailer: Lotus Notes Release 5.0.3 (Intl) 21 March 2000 Message-ID: From: "Bulent Abali" Date: Thu, 9 Aug 2001 10:26:22 -0400 X-MIMETrack: Serialize by Router on D01ML233/01/M/IBM(Release 5.0.8 |June 18, 2001) at 08/09/2001 10:25:14 AM MIME-Version: 1.0 Content-type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >In such a scenario I would disagree with Alan that network paging is >high latency as compared to disk access. I have a fully switched 100 Mpbs >full-duplex ethernet network, and sending a page across the net into >the memory of a fast server could have much less latency that writing >that page out to a local old, slow IDE disk. Have you actually tried swapping over the network using nbd or any other network device mounted as a swap disk? Never mind the latency. Does it work at all? I am curious to know. Last time I checked swapping over nbd required patching the network stack. Because swapping occurs when memory is low and when memory is low TCP doesn't do what you expect it to do... Bulent