From: Wendy Cheng Subject: Re: [NFS] NFS Digest, Vol 18, Issue 70 (NFS performance problems) Date: Fri, 30 Nov 2007 11:27:16 -0500 Message-ID: <475039E4.5070903@redhat.com> References: <47434ED7.4010100@redhat.com> <47435049.1010800@redhat.com> <47445727.5090705@oracle.com> <474A3D6B.2060208@redhat.com> <20071126050230.GD21120@fieldses.org> <18254.19187.470275.538680@notabene.brown> <1196314230.7950.42.camel@heimdal.trondhjem.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: "J. Bruce Fields" , chuck.lever@oracle.com, nfs@lists.sourceforge.net, NeilBrown To: Trond Myklebust Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1Iy8ls-0006WB-SD for nfs@lists.sourceforge.net; Fri, 30 Nov 2007 08:31:20 -0800 Received: from mx1.redhat.com ([66.187.233.31]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1Iy8ly-0003aM-Gq for nfs@lists.sourceforge.net; Fri, 30 Nov 2007 08:31:26 -0800 In-Reply-To: <1196314230.7950.42.camel-rJ7iovZKK19ZJLDQqaL3InhyD016LWXt@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: Trond Myklebust wrote: > Actually, the real problem would be dealing with something like > unlink('foo') followed by open('foo', O_CREAT|O_EXCL). How do you ensure > that a replay of those actions following a reboot is fully consistent in > the face of some other client attempting an open('foo', O_CREAT) at the > same time? > > The problem is that a number of directory operations involve exclusive > semantics, and so cannot be replayed. The solution to this sort of > problem is going to have to involve exclusive (i.e. write) directory > delegations to ensure that whatever transactions one client performs > cannot interfere with the transactions performed by another. > > Well, a dumb question from me (borrowing Bruce's line :) ) ... even with "sync" in place, when server rebooted, the RPC reply cache is gone. How does linux server handle re-transmitted non-idempotent requests ? -- Wendy ------------------------------------------------------------------------- SF.Net email is sponsored by: The Future of Linux Business White Paper from Novell. From the desktop to the data center, Linux is going mainstream. Let it simplify your IT future. http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs _______________________________________________ Please note that nfs@lists.sourceforge.net is being discontinued. Please subscribe to linux-nfs@vger.kernel.org instead. http://vger.kernel.org/vger-lists.html#linux-nfs