From mboxrd@z Thu Jan  1 00:00:00 1970
From: Theodore Ts'o <tytso-3s7WtUTddSA@public.gmane.org>
Subject: Re: light weight write barriers
Date: Mon, 5 Nov 2012 17:04:40 -0500
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To: Pavel Machek <pavel-+ZI9xUNit7I@public.gmane.org>
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On Mon, Nov 05, 2012 at 09:03:48PM +0100, Pavel Machek wrote:
> > Well, using data journalling with ext3/4 may do what you want.  If you
> > don't do any fsync, the changes will get written every 5 seconds when
> > the automatic journal sync happens (and sub-4k writes will also get
> 
> Hmm. But that would need setting journalling mode per-file, no?
> 
> Like, make it journal data for all the databases, but keep normal mode
> for rest of system...

You can do that, using "chattr +j file.db".  It's apparently not a
well known feature of ext3/4....

						- Ted