Re: [nfsv4] Review of 3530bis "Multi-Server Namespace" Chapter

<david.noveck@emc.com> Fri, 22 October 2010 06:32 UTC

Return-Path: <david.noveck@emc.com>
X-Original-To: nfsv4@core3.amsl.com
Delivered-To: nfsv4@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id AB0F43A6405 for <nfsv4@core3.amsl.com>; Thu, 21 Oct 2010 23:32:53 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -6.668
X-Spam-Level:
X-Spam-Status: No, score=-6.668 tagged_above=-999 required=5 tests=[AWL=-0.069, BAYES_00=-2.599, RCVD_IN_DNSWL_MED=-4]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id K209UY+gn6XG for <nfsv4@core3.amsl.com>; Thu, 21 Oct 2010 23:32:52 -0700 (PDT)
Received: from mexforward.lss.emc.com (mexforward.lss.emc.com [128.222.32.20]) by core3.amsl.com (Postfix) with ESMTP id 4EE9B3A6847 for <nfsv4@ietf.org>; Thu, 21 Oct 2010 23:32:52 -0700 (PDT)
Received: from hop04-l1d11-si03.isus.emc.com (HOP04-L1D11-SI03.isus.emc.com [10.254.111.23]) by mexforward.lss.emc.com (Switch-3.4.3/Switch-3.4.3) with ESMTP id o9M6YSIh018711 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 22 Oct 2010 02:34:28 -0400
Received: from mailhub.lss.emc.com (mailhub.lss.emc.com [10.254.222.226]) by hop04-l1d11-si03.isus.emc.com (RSA Interceptor); Fri, 22 Oct 2010 02:34:21 -0400
Received: from corpussmtp5.corp.emc.com (corpussmtp5.corp.emc.com [128.221.166.229]) by mailhub.lss.emc.com (Switch-3.4.3/Switch-3.4.3) with ESMTP id o9M6YHkw018441; Fri, 22 Oct 2010 02:34:17 -0400
Received: from CORPUSMX50A.corp.emc.com ([128.221.62.45]) by corpussmtp5.corp.emc.com with Microsoft SMTPSVC(6.0.3790.4675); Fri, 22 Oct 2010 02:34:17 -0400
x-mimeole: Produced By Microsoft Exchange V6.5
Content-class: urn:content-classes:message
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
Date: Fri, 22 Oct 2010 02:34:15 -0400
Message-ID: <BF3BB6D12298F54B89C8DCC1E4073D80028C7176@CORPUSMX50A.corp.emc.com>
In-Reply-To: <alpine.LFD.2.00.1010212156150.4707@jlentini-linux.nane.netapp.com>
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
Thread-Topic: Review of 3530bis "Multi-Server Namespace" Chapter
Thread-Index: ActxjokZqKJv3GUISGu1X++GHNk9wwAI4vCQ
References: <alpine.LFD.2.00.1009221101060.21841@jlentini-linux.nane.netapp.com> <9F6B463A-0CA8-4C34-A7C2-0BF108745B94@netapp.com> <alpine.LFD.2.00.1010211446060.4707@jlentini-linux.nane.netapp.com> <BF3BB6D12298F54B89C8DCC1E4073D80028C7166@CORPUSMX50A.corp.emc.com> <alpine.LFD.2.00.1010212156150.4707@jlentini-linux.nane.netapp.com>
From: david.noveck@emc.com
To: jlentini@netapp.com
X-OriginalArrivalTime: 22 Oct 2010 06:34:17.0261 (UTC) FILETIME=[26B40DD0:01CB71B3]
X-EMM-MHVC: 1
Cc: Robert.Thurlow@oracle.com, nfsv4@ietf.org
Subject: Re: [nfsv4] Review of 3530bis "Multi-Server Namespace" Chapter
X-BeenThere: nfsv4@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: NFSv4 Working Group <nfsv4.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/nfsv4>, <mailto:nfsv4-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/nfsv4>
List-Post: <mailto:nfsv4@ietf.org>
List-Help: <mailto:nfsv4-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/nfsv4>, <mailto:nfsv4-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 22 Oct 2010 06:32:54 -0000

> I must not have been clear, because I think I'm saying the 
> same thing as you and Trond. 

Well, if you are, then you just have to be correct :-)

> My observation was that for the other equivalence classes 
> (e.g., handle class) the specification gives rules for all 
> three cases (replication, migration, and referrals), but 
> for the write-verifier only rules for the replication and 
> migration cases are given. The question was if specification 
> should explicitly state that the referral case doesn't apply 
> to the write-verifier class. 

I think it would make things clearer.  It probably should.

> I don't have an opinion on this. 

Come on.  Take a stand. :-)

> When I was reviewing this chapter, I wondered if 
> this was intentional.

It was laziness.  I'm not sure if there is a good way to distinguish
intentional from unintentional laziness.

-----Original Message-----
From: James Lentini [mailto:jlentini@netapp.com] 
Sent: Thursday, October 21, 2010 10:11 PM
To: Noveck, David
Cc: thomas@netapp.com; Robert Thurlow; nfsv4@ietf.org
Subject: RE: Review of 3530bis "Multi-Server Namespace" Chapter


On Thu, 21 Oct 2010, david.noveck@emc.com wrote:

> I'm using the term "referral" to indicate a situation in which the
> client does not have any state within the target filesystem.  If he
> doesn't have an open file, how is he writing?  I don't think the
> write-verifier case can arise in a referral.
> 
> Am I missing something here?

I must not have been clear, because I think I'm saying the same thing 
as you and Trond.

My observation was that for the other equivalence classes (e.g., 
handle class) the specification gives rules for all three cases 
(replication, migration, and referrals), but for the write-verifier 
only rules for the replication and migration cases are given. The 
question was if specification should explicitly state that the 
referral case doesn't apply to the write-verifier class. I don't have 
an opinion on this. When I was reviewing this chapter, I wondered if 
this was intentional.


> -----Original Message-----
> From: James Lentini [mailto:jlentini@netapp.com] 
> Sent: Thursday, October 21, 2010 3:07 PM
> To: Thomas Haynes
> Cc: Robert Thurlow; Noveck, David; nfsv4@ietf.org
> Subject: Re: Review of 3530bis "Multi-Server Namespace" Chapter
> 
> 
> 
> On Wed, 13 Oct 2010, Thomas Haynes wrote:
> 
> > Rob and Dave,
> > 
> > There is a question for each of you below.
> > 
> > 
> > On Sep 22, 2010, at 6:31 PM, James Lentini wrote:
> > 
> <snip>
> > 
> >       For the write-verifier class in Section 7.7.7, Section 7.9.1
> >       recommends assuming file system instances are of a different
> >       class in the case of a failover. Is there a recommendation for

> >       the NFS4ERR_MOVED case? I realize that the recommendations in 
>             ^^^^^^^^^^^^^
>             referral
> 
> 
> To clarify my question: Is there a recommendation for the 
> write-verifier class in the referral case?
> 
> The "general" rules for the handle class, fileid class, and change 
> class cover the replication, migration, and referral cases. Since 
> those rules immediately precede the write-verifier rules, the omission

> of a referral case jumped out at me.
> 
> I expect the recommendation would be for the client to treat the 
> referral source and referral target as being in different 
> write-verifier classes given that the write-verifier class doesn't 
> apply to the referral case, but the text doesn't say that.
> 
> 
> 
> >       7.9.1 are taken almost verbatim from RFC 5661, but it seems 
> >       that there is a case missing here.
> > 
> > Rob, any comment here?
> 
>