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Date: Fri, 7 Feb 2014 09:14:50 +0530
From: Bharata B Rao <bharata@linux.vnet.ibm.com>
Message-ID: <20140207034450.GB3787@in.ibm.com>
References: <cover.1391541706.git.jcody@redhat.com>
	<925f4c0a62291c070991d1b3e75a770de986a686.1391541706.git.jcody@redhat.com>
	<20140205192535.GA3440@irqsave.net>
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In-Reply-To: <20140205192535.GA3440@irqsave.net>
Subject: Re: [Qemu-devel] [PATCH 1/2] block: gluster - code movements,
 state storage changes
Reply-To: bharata@linux.vnet.ibm.com
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To: =?iso-8859-1?Q?Beno=EEt?= Canet <benoit.canet@irqsave.net>
Cc: kwolf@redhat.com, Jeff Cody <jcody@redhat.com>, qemu-devel@nongnu.org, stefanha@redhat.com

On Wed, Feb 05, 2014 at 08:25:36PM +0100, Benoît Canet wrote:
> Le Tuesday 04 Feb 2014 à 14:26:58 (-0500), Jeff Cody a écrit :
> >  
> > +static void qemu_gluster_parse_flags(int bdrv_flags, int *open_flags)
> > +{
> > +    assert(open_flags != NULL);
> > +
> > +    *open_flags |= O_BINARY;
> > +
> > +    if (bdrv_flags & BDRV_O_RDWR) {
> > +        *open_flags |= O_RDWR;
> > +    } else {
> > +        *open_flags |= O_RDONLY;
> > +    }
> > +
> > +    if ((bdrv_flags & BDRV_O_NOCACHE)) {
> > +        *open_flags |= O_DIRECT;
> > +    }
> > +}
> 
> I saw the enable-O_SYNC option here.
> http://www.gluster.org/community/documentation/index.php/Translators/performance
> Why the gluster driver does not allow to enable O_SYNC ?

I am not aware of any option in QEMU (like cache= etc) that will force
block driver (like gluster) to use O_SYNC. Do other drivers use O_SYNC ?

Turning off write-behind for the entire gluster volume isn't an option ?

Regards,
Bharata.