<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 14 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
        {font-family:Calibri;
        panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
        {margin:0in;
        margin-bottom:.0001pt;
        font-size:11.0pt;
        font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
        {mso-style-priority:99;
        color:blue;
        text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
        {mso-style-priority:99;
        color:purple;
        text-decoration:underline;}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
        {mso-style-priority:34;
        margin-top:0in;
        margin-right:0in;
        margin-bottom:0in;
        margin-left:.5in;
        margin-bottom:.0001pt;
        font-size:11.0pt;
        font-family:"Calibri","sans-serif";}
span.EmailStyle18
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:windowtext;}
span.EmailStyle19
        {mso-style-type:personal-reply;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
.MsoChpDefault
        {mso-style-type:export-only;
        font-size:10.0pt;}
@page WordSection1
        {size:8.5in 11.0in;
        margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
        {page:WordSection1;}
/* List Definitions */
@list l0
        {mso-list-id:567107156;
        mso-list-type:hybrid;
        mso-list-template-ids:1264881842 67698703 67698713 67698715 67698703 67698713 67698715 67698703 67698713 67698715;}
@list l0:level1
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l0:level2
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l0:level3
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        text-indent:-9.0pt;}
@list l0:level4
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l0:level5
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l0:level6
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        text-indent:-9.0pt;}
@list l0:level7
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l0:level8
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l0:level9
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        text-indent:-9.0pt;}
@list l1
        {mso-list-id:1148747319;
        mso-list-type:hybrid;
        mso-list-template-ids:879755540 67698713 67698713 67698715 67698703 67698713 67698715 67698703 67698713 67698715;}
@list l1:level1
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l1:level2
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l1:level3
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        text-indent:-9.0pt;}
@list l1:level4
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l1:level5
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l1:level6
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        text-indent:-9.0pt;}
@list l1:level7
        {mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l1:level8
        {mso-level-number-format:alpha-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:left;
        text-indent:-.25in;}
@list l1:level9
        {mso-level-number-format:roman-lower;
        mso-level-tab-stop:none;
        mso-level-number-position:right;
        text-indent:-9.0pt;}
ol
        {margin-bottom:0in;}
ul
        {margin-bottom:0in;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal">   Please advise me whether the following scenario requires changes to nova scheduler or can be handled with existing scheduling mechanisms.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have a type of PCIe device (not necessarily a NIC or HBA). The device can be configured with a set of user-defined resources – say A, B, C. Each resource can be shared between a limited number of VMs -- say A can be shared among 4 VMs,
 B among 8, etc. A VM image may request the need for a specific list of features, say A and B. Then I want to place the VM on a host according to these criteria:<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">1.<span style="font:7.0pt "Times New Roman"">      
</span></span><![endif]>If there are hosts with a PCIe device that already has A and B configured, and has a free instance each of A and B, the VM  must be placed on one of those hosts.<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">2.<span style="font:7.0pt "Times New Roman"">      
</span></span><![endif]>Otherwise, find a host with this PCIe device that can be configured with one instance each of A and B.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">It is not clear that this can be handled through 3<sup>rd</sup> party metadata. Suppose we create host aggregates with properties like “resource=A” and “resource=B”, and also associate properties like “resource=A” with VM images. (A and
 B are UUIDs representing user-defined resources.) <span style="color:#1F497D">Perhaps
</span>Nova scheduler can match the properties to select host aggregates that have all properties that the VM requires. However:<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l1 level1 lfo4"><![if !supportLists]><span style="mso-list:Ignore">a.<span style="font:7.0pt "Times New Roman"">      
</span></span><![endif]>This would not be dynamic (i.e. track the free instances of each resource), and<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l1 level1 lfo4"><![if !supportLists]><span style="mso-list:Ignore">b.<span style="font:7.0pt "Times New Roman"">     
</span></span><![endif]>This addresses only #1 above.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Is there any way I can leverage existing scheduler mechanisms to  solve this VM placement problem? If not, do you have thoughts/comments on what changes are needed?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks, and apologies in advance if I am not clear. Please feel free to ask questions.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Cheers,<o:p></o:p></p>
<p class="MsoNormal">Sundar<span style="color:#1F497D"><o:p></o:p></span></p>
</div>
<br>
<hr>
<font face="Arial" color="Black" size="2"><br>
Confidentiality Notice.<br>
This message may contain information that is confidential or otherwise protected from disclosure. If you are not the intended recipient, you are hereby notified that any use, disclosure, dissemination, distribution, or copying of this message, or any attachments,
 is strictly prohibited. If you have received this message in error, please advise the sender by reply e-mail, and delete the message and any attachments. Thank you.<br>
</font>
</body>
</html>