<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=utf-8">
<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;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","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.MsoAcetate, li.MsoAcetate, div.MsoAcetate
{mso-style-priority:99;
mso-style-link:"Balloon Text Char";
margin:0in;
margin-bottom:.0001pt;
font-size:8.0pt;
font-family:"Tahoma","sans-serif";}
span.EmailStyle17
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
span.BalloonTextChar
{mso-style-name:"Balloon Text Char";
mso-style-priority:99;
mso-style-link:"Balloon Text";
font-family:"Tahoma","sans-serif";}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></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"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Before I try these mmfsctl commands, what are the implications of suspending writes? I assume the entire file system will be quiesced? What if NSD clients
are non responsive to this operation? Does a deadlock occur or is there a risk of a deadlock?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Thanks in advance!<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">-Bryan
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> gpfsug-discuss-bounces@gpfsug.org [mailto:gpfsug-discuss-bounces@gpfsug.org]
<b>On Behalf Of </b>makaplan@us.ibm.com<br>
<b>Sent:</b> Friday, August 28, 2015 11:55 AM<br>
<b>To:</b> gpfsug-discuss@gpfsug.org<br>
<b>Cc:</b> gpfsug-discuss@gpfsug.org<br>
<b>Subject:</b> Re: [gpfsug-discuss] Unix mode bits and mmapplypolicy<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Arial","sans-serif"">This is due to a design trade-off in mmapplypolicy. <o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Arial","sans-serif"">Mmapplypolicy bypasses locks and caches - so it doesn't "see" inode&metadata changes until they are flushed to disk.<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Arial","sans-serif"">I believe this is hinted at in our publications.<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Arial","sans-serif""> <o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Arial","sans-serif"">You can force a flush with`mmfsctl fsname suspend-write; mmfsctl fsname resume`<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Arial","sans-serif""> <o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Arial","sans-serif""> <o:p></o:p></span></p>
</div>
<blockquote style="border:none;border-left:solid #AAAAAA 1.5pt;padding:0in 0in 0in 4.0pt;margin-left:3.75pt;margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Arial","sans-serif"">----- Original message -----<br>
From: aquan <<a href="mailto:aquan@o2.pl">aquan@o2.pl</a>><br>
Sent by: <a href="mailto:gpfsug-discuss-bounces@gpfsug.org">gpfsug-discuss-bounces@gpfsug.org</a><br>
To: <a href="mailto:gpfsug-discuss@gpfsug.org">gpfsug-discuss@gpfsug.org</a><br>
Cc:<br>
Subject: [gpfsug-discuss] Unix mode bits and mmapplypolicy<br>
Date: Fri, Aug 28, 2015 11:12 AM<br>
<br>
Hello,<br>
<br>
This is my first time here. I'm a computer science student from Poland<br>
and I use GPFS during my internship at DESY. GPFS is a completely new<br>
experience to me, I don't know much about file systems and especially those<br>
used on clusters.<br>
I would like to ask about the unix mode bits and mmapplypolicy.<br>
What I noticed is that when I do the following:<br>
<br>
1. Recursively call chmod on some directory (i.e. chmod -R 0777 some_directory)<br>
2. Call mmapplypolicy to list mode (permissions),<br>
<br>
the listed modes of files don't correspond exactly to the modes that I set with chmod.<br>
However, if I wait a bit between step 1 and 2, the listed modes are correct.<br>
It seems that the mode bits are updated somewhat asynchronically and if I run<br>
mmapplypolicy too soon, they will contain old values.<br>
<br>
I would like to ask if it is possible to make sure that before calling mmputacl,<br>
the mode bits of that directory will be up to date on the list generated by a policy?<br>
<br>
- Omer Sakarya <o:p></o:p></span></p>
<div>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">_______________________________________________<br>
gpfsug-discuss mailing list<br>
gpfsug-discuss at gpfsug.org<br>
<a href="http://gpfsug.org/mailman/listinfo/gpfsug-discuss" target="_blank">http://gpfsug.org/mailman/listinfo/gpfsug-discuss</a></span><span style="font-size:10.5pt;font-family:"Arial","sans-serif""><o:p></o:p></span></p>
</div>
</blockquote>
<div>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Arial","sans-serif""> <o:p></o:p></span></p>
</div>
</div>
</div>
<br>
<hr>
<font face="Arial" color="Gray" size="1"><br>
Note: This email is for the confidential use of the named addressee(s) only and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you are hereby notified that any review, dissemination or copying of this
email is strictly prohibited, and to please notify the sender immediately and destroy this email and any attachments. Email transmission cannot be guaranteed to be secure or error-free. The Company, therefore, does not make any guarantees as to the completeness
or accuracy of this email or any attachments. This email is for informational purposes only and does not constitute a recommendation, offer, request or solicitation of any kind to buy, sell, subscribe, redeem or perform any type of transaction of a financial
product.<br>
</font>
</body>
</html>