NFSv4 delegations criteria? Fwd: Tuning Linux NFSv4 for high latency connections?

NFSv4 delegations criteria? Fwd: Tuning Linux NFSv4 for high latency connections?

[Cedric Blancher]

What are the criteria for grating a file delegation in NFSv4? Are file
delegations retained even if a process closes a file and the next
process in the chain opens it again (e.g. in a shell script)?

Ced

PS: Who again grants NFSv4 delegations? Server or client? Do
delegations work when data are appended at the end of a file?

---------- Forwarded message ----------
From: Cedric Blancher <cedric.blancher@gmail.com>
Date: 23 April 2014 20:01
Subject: Tuning Linux NFSv4 for high latency connections?
To: Linux NFS Mailing List <linux-nfs@vger.kernel.org>


Are there any options to improve the Linux NFSv4 performance over a
high latency connection?

We currently use Solaris/Illumos as NFSv4 server and client over a
cross continental Internet connection. Latency is terrible (~220ms)
but the counter this by running work in parallel so the latency is
mostly mitigated.

We now wish to migrate (short: Away from Oracle because support is
basically unbearable) to Linux (tested SuSE 13.1 and current Fedora)
and build times are 17 times (!!!) SLOWER than on Solaris/Illumos.

Are there any tunables besides actimeo=300?

Ced
--
Cedric Blancher <cedric.blancher@gmail.com>
Institute Pasteur


-- 
Cedric Blancher <cedric.blancher@gmail.com>
Institute Pasteur

Re: NFSv4 delegations criteria? Fwd: Tuning Linux NFSv4 for high latency connections?

[Cedric Blancher]

Anyone?

Ced

On 23 April 2014 23:03, Cedric Blancher <cedric.blancher@gmail.com> wrote:
> What are the criteria for grating a file delegation in NFSv4? Are file
> delegations retained even if a process closes a file and the next
> process in the chain opens it again (e.g. in a shell script)?
>
> Ced
>
> PS: Who again grants NFSv4 delegations? Server or client? Do
> delegations work when data are appended at the end of a file?
>
> ---------- Forwarded message ----------
> From: Cedric Blancher <cedric.blancher@gmail.com>
> Date: 23 April 2014 20:01
> Subject: Tuning Linux NFSv4 for high latency connections?
> To: Linux NFS Mailing List <linux-nfs@vger.kernel.org>
>
>
> Are there any options to improve the Linux NFSv4 performance over a
> high latency connection?
>
> We currently use Solaris/Illumos as NFSv4 server and client over a
> cross continental Internet connection. Latency is terrible (~220ms)
> but the counter this by running work in parallel so the latency is
> mostly mitigated.
>
> We now wish to migrate (short: Away from Oracle because support is
> basically unbearable) to Linux (tested SuSE 13.1 and current Fedora)
> and build times are 17 times (!!!) SLOWER than on Solaris/Illumos.
>
> Are there any tunables besides actimeo=300?
>
> Ced
> --
> Cedric Blancher <cedric.blancher@gmail.com>
> Institute Pasteur
>
>
> --
> Cedric Blancher <cedric.blancher@gmail.com>
> Institute Pasteur



-- 
Cedric Blancher <cedric.blancher@gmail.com>
Institute Pasteur

Re: NFSv4 delegations criteria? Fwd: Tuning Linux NFSv4 for high latency connections?

[J. Bruce Fields]

On Mon, Jul 07, 2014 at 06:24:41PM +0200, Cedric Blancher wrote:
> Anyone?
> 
> Ced
> 
> On 23 April 2014 23:03, Cedric Blancher <cedric.blancher@gmail.com> wrote:
> > What are the criteria for grating a file delegation in NFSv4?

They're generally implementation-specific.

> > Are file
> > delegations retained even if a process closes a file and the next
> > process in the chain opens it again (e.g. in a shell script)?

Yes, they can be.

> >
> > Ced
> >
> > PS: Who again grants NFSv4 delegations? Server or client?

The server.

> > Do
> > delegations work when data are appended at the end of a file?

The holder of a write delegation can append, yes.

The rfc's (3530 and 5661) have some more details.

I suspect the Solaris server supports write delegations.  The Linux
server doesn't.

Hard to tell the reason for the performance difference you describe,
though, you'd probably need to gather some statistics.

--b.

> >
> > ---------- Forwarded message ----------
> > From: Cedric Blancher <cedric.blancher@gmail.com>
> > Date: 23 April 2014 20:01
> > Subject: Tuning Linux NFSv4 for high latency connections?
> > To: Linux NFS Mailing List <linux-nfs@vger.kernel.org>
> >
> >
> > Are there any options to improve the Linux NFSv4 performance over a
> > high latency connection?
> >
> > We currently use Solaris/Illumos as NFSv4 server and client over a
> > cross continental Internet connection. Latency is terrible (~220ms)
> > but the counter this by running work in parallel so the latency is
> > mostly mitigated.
> >
> > We now wish to migrate (short: Away from Oracle because support is
> > basically unbearable) to Linux (tested SuSE 13.1 and current Fedora)
> > and build times are 17 times (!!!) SLOWER than on Solaris/Illumos.
> >
> > Are there any tunables besides actimeo=300?
> >
> > Ced
> > --
> > Cedric Blancher <cedric.blancher@gmail.com>
> > Institute Pasteur
> >
> >
> > --
> > Cedric Blancher <cedric.blancher@gmail.com>
> > Institute Pasteur
> 
> 
> 
> -- 
> Cedric Blancher <cedric.blancher@gmail.com>
> Institute Pasteur
> --
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