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From: "Daniel P. Berrange" <berrange@redhat.com>
To: Ian Pratt <Ian.Pratt@cl.cam.ac.uk>
Cc: xen-devel@lists.xensource.com,
	Akio Takebe <takebe_akio@jp.fujitsu.com>,
	John Levon <levon@movementarian.org>,
	Rikiya Ayukawa <ayukawa@sde.cs.titech.ac.jp>,
	Rikiya Ayukawa <ayukawa.rikiya@np.css.fujitsu.com>,
	SUZUKI Kazuhiro <kaz@jp.fujitsu.com>
Subject: Re: [PATCH][RFC] making "xm dump-core" paralell
Date: Fri, 28 Sep 2007 21:07:46 +0100	[thread overview]
Message-ID: <20070928200746.GE14112@redhat.com> (raw)
In-Reply-To: <8A87A9A84C201449A0C56B728ACF491E260893@liverpoolst.ad.cl.cam.ac.uk>

On Fri, Sep 28, 2007 at 08:53:01PM +0100, Ian Pratt wrote:
> > > xm save/restore also fork+exec. I think it's the same reason.
> > > Is that right, Keir?
> > 
> > My understanding is that the only reason we have separate binaries for
> > that is because in the past save/restore was unstable, and had a
> > tendency to crash xend.
> 
> I can't see much downside to having a separate process. It makes it
> easier to ionice the IO etc.

Well the fact that XenD has to parse the STDOUT from these processes applying
a regex of '^ERROR:' in an attempt to try and catch errors is one fairly 
large downside.  Combine that with the incredibly complex interactions
between XenD and QEMU, again with tricky error reporting and the result is
a pretty hard thing to debug.

Dan.
-- 
|=- Red Hat, Engineering, Emerging Technologies, Boston.  +1 978 392 2496 -=|
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  parent reply	other threads:[~2007-09-28 20:07 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-09-27  8:36 [PATCH][RFC] making "xm dump-core" paralell Rikiya Ayukawa
2007-09-27 14:26 ` John Levon
2007-09-28 11:02   ` Akio Takebe
2007-09-28 17:24     ` John Levon
2007-09-28 19:53       ` Ian Pratt
2007-09-28 20:06         ` John Levon
2007-09-28 20:07         ` Daniel P. Berrange [this message]
  -- strict thread matches above, loose matches on Subject: below --
2007-09-27  2:12 Rikiya Ayukawa
2007-09-27  6:26 ` John Levon
2007-09-27  7:39 ` Keir Fraser

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