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 A26AF7F37 for ; Wed, 8 Jul 2015 21:43:45 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay2.corp.sgi.com (Postfix) with ESMTP id 7001A304043 for ; Wed, 8 Jul 2015 19:43:42 -0700 (PDT) Message-ID: <559ddfd7.293e460a.833d.ffffb57c@mx.google.com> MIME-Version: 1.0 From: rakesh patel Subject: RE: regarding journaling mode Date: Thu, 9 Jul 2015 08:13:10 +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="===============2882028352345891551==" Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: xfs-owner@oss.sgi.com, xfs@oss.sgi.com --===============2882028352345891551== Content-Type: multipart/alternative; boundary="_41924495-2CEA-4DBE-AA2E-FDD6ACA45652_" --_41924495-2CEA-4DBE-AA2E-FDD6ACA45652_ Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" How Metadata updates after data IO completion done? Write back mode does no= t support synchronization? Is there any other feature ?? -----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 --_41924495-2CEA-4DBE-AA2E-FDD6ACA45652_ Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="utf-8"
How Metadata updates after data IO completion done? Write= back mode does not support synchronization?

Is there any other feat= ure ??
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: rega= rding journaling mode

On Mon, Jul 06, 2015 at 11:38:32A= M +0530, Rakesh Patel wrote:
> Hi,
>
> I come to know XF= S is using writeback journaling mode.

Can you explain how you came t= o that conclusion?

> As per the
> journaling guide, writeba= ck is unsafe which does not preserve data and
> metadata write synchr= onization.

What journalling guide would that be? Please quote your s= ources when
asking questions.

> I really want to know reason b= ehind to choose writeback mode for journaling
> in XFS.

Metada= ta updates after data IO completion are used instead of
ordering data wr= iteback operations through the journal.

Cheers,

Dave.
-- <= br>Dave Chinner
david@fromorbit.com
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