From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sylar Shen Subject: The cache problem of re-export NFS test Date: Tue, 12 Apr 2011 22:57:22 +0800 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Received: from mail-bw0-f46.google.com ([209.85.214.46]:53470 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757216Ab1DLO5X (ORCPT ); Tue, 12 Apr 2011 10:57:23 -0400 Received: by bwz15 with SMTP id 15so5432899bwz.19 for ; Tue, 12 Apr 2011 07:57:22 -0700 (PDT) Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel Hi developers, I know that the following question may not be relative to Ceph but this confuses me a lot. I am testing the function of re-exporting nfs by command "dd" without using buffer. That means I would like my data to be written to Ceph DFS directly without passing by the buffer of client or nfs-client. Here is my test architecture. Hope you could understand what I am trying to express.....:p ------------------------------------------------------------------------------ nfs ceph protocol Client <------------>Ceph-Client <-------------------> Ceph DFS ------------------------------------------------------------------------------ I used the command "dd if=/dev/zero of=/mnt/ceph/test bs=64k count=10000 oflag=dsync" My purpose was to write the data from the client to Ceph DFS through Ceph-client. Ceph DFS was mounted by Ceph-client using Ceph protocol and Ceph-client was mounted by client using nfs protocol. I know that my dd command with argument oflag=dsync would write the data to Ceph-client without using buffer on the client. But I want my Ceph-client could also just pass the data to Ceph DFS without using its buffer. So.....is there any way I can run my scenario? Or in other words, is there any method I can assure that Ceph-client won't do the buffer task itself? Thank you~~ -- Best Regards, Sylar Shen