From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id ECEA97F4E for ; Mon, 6 Jul 2015 21:51:29 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay2.corp.sgi.com (Postfix) with ESMTP id D94BA304066 for ; Mon, 6 Jul 2015 19:51:29 -0700 (PDT) Received: from mail-pa0-f41.google.com (mail-pa0-f41.google.com [209.85.220.41]) by cuda.sgi.com with ESMTP id Dn29RHWagK9d3tBt (version=TLSv1 cipher=RC4-SHA bits=128 verify=NO) for ; Mon, 06 Jul 2015 19:51:25 -0700 (PDT) Received: by pacws9 with SMTP id ws9so106387615pac.0 for ; Mon, 06 Jul 2015 19:51:24 -0700 (PDT) Message-ID: <559b3eab.46f0440a.bad8e.7195@mx.google.com> MIME-Version: 1.0 From: rakesh patel Subject: RE: regarding journaling mode Date: Tue, 7 Jul 2015 08:21:16 +0530 In-Reply-To: <20150707002430.GV7943@dastard> References: <20150707002430.GV7943@dastard> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============4075747192894380250==" Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: xfs@oss.sgi.com --===============4075747192894380250== Content-Type: multipart/alternative; boundary="_5C4CE296-BE70-44B1-9754-48BEBA71448B_" --_5C4CE296-BE70-44B1-9754-48BEBA71448B_ Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" How metadata is committed only after data? Is there any other file system f= eature? Because write back mode does not preserve it? Rakesh -----Original Message----- From: "Dave Chinner" Sent: =E2=80=8E07-=E2=80=8E07-=E2=80=8E2015 05:59 To: "Rakesh Patel" Cc: "xfs@oss.sgi.com" Subject: Re: regarding journaling mode On Mon, Jul 06, 2015 at 11:38:32AM +0530, Rakesh Patel wrote: > Hi, >=20 > I come to know XFS is using writeback journaling mode. Can you explain how you came to that conclusion? > As per the > journaling guide, writeback is unsafe which does not preserve data and > metadata write synchronization. What journalling guide would that be? Please quote your sources when asking questions. > I really want to know reason behind to choose writeback mode for journali= ng > in XFS. Metadata updates after data IO completion are used instead of ordering data writeback operations through the journal. Cheers, Dave. --=20 Dave Chinner david@fromorbit.com --_5C4CE296-BE70-44B1-9754-48BEBA71448B_ Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="utf-8"
How metadata is committed only after data? Is there any o= ther file system feature? Because write back mode does not preserve it?
=
Rakesh
From: Dave Chinner
Sent: =E2=80=8E07-= =E2=80=8E07-=E2=80=8E2015 05:59
To: Rakesh Patel
Cc: xfs@oss.sgi.com
Subject: Re: = regarding journaling mode

On Mon, Jul 06, 2015 at 11:38= :32AM +0530, Rakesh Patel wrote:
> Hi,
>
> I come to kno= w XFS is using writeback journaling mode.

Can you explain how you ca= me to that conclusion?

> As per the
> journaling guide, wri= teback is unsafe which does not preserve data and
> metadata write sy= nchronization.

What journalling guide would that be? Please quote yo= ur sources when
asking questions.

> I really want to know reas= on behind to choose writeback mode for journaling
> in XFS.

Me= tadata updates after data IO completion are used instead of
ordering dat= a writeback operations through the journal.

Cheers,

Dave.
= --
Dave Chinner
david@fromorbit.com
= --_5C4CE296-BE70-44B1-9754-48BEBA71448B_-- --===============4075747192894380250== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs --===============4075747192894380250==--