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Subject: Re: [ckrm-tech] [PATCH] BC: resource beancounters (v4) (added	user
	memory)
From: Chandra Seetharaman <sekharan@us.ibm.com>
Reply-To: sekharan@us.ibm.com
To: Pavel Emelianov <xemul@openvz.org>
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Date: Mon, 11 Sep 2006 11:49:50 -0700
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On Mon, 2006-09-11 at 12:13 +0400, Pavel Emelianov wrote:

<snip>
> >
> > Don't start the new container or change the guarantees of the existing
> > ones
> > to accommodate this one :) The QoS design (done by the administrator)
> > should
> > take care of such use-cases. It would be perfectly ok to have a container
> > that does not care about guarantees to set their guarantee to 0 and set
> > their limit to the desired value. As Chandra has been stating we need two
> > parameters (guarantee, limit), either can be optional, but not both.
> If I set up 9 groups to have 100Mb limit then I have 100Mb assured (on
> 1Gb node)
> for the 10th one exactly. And I do not have to set up any guarantee as
> it won't affect
> anything. So what a guarantee parameter is needed for?

I do not think it is that simple since
 - there is typically more than one class I want to set guarantee to
 - I will not able to use both limit and guarantee
 - Implementation will not be work-conserving.

Also, How would you configure the following in your model ?

5 classes: Class A(10, 40), Class B(20, 100), Class C (30, 100), Class D
(5, 100), Class E(15, 50); (class_name(guarantee, limit))

"Limit only" approach works for DoS prevention. But for providing QoS
you would need guarantee.
-- 

----------------------------------------------------------------------
    Chandra Seetharaman               | Be careful what you choose....
              - sekharan@us.ibm.com   |      .......you may get it.
----------------------------------------------------------------------


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