<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<style>pre,code,address {
margin: 0px;
}
h1,h2,h3,h4,h5,h6 {
margin-top: 0.2em;
margin-bottom: 0.2em;
}
ol,ul {
margin-top: 0em;
margin-bottom: 0em;
}
blockquote {
margin-top: 0em;
margin-bottom: 0em;
}
</style>
</head>
<body>
<div>Hello,</div>
<div><br>
</div>
<div>We've encountered yet another performance flaw. We have a GPFS filesystem mounted using GPFS binaries on Windows. When we try to rewrite a file on the GPFS filesystem rewriting speed is much slower than writing to a new file. The difference ratio we measured
is about 3.5 times. From the task manager it is visible that there is excessive amount of reading from the network when rewriting. This is even visible on the NDS server as io activity. However when rewriting on a linux client there are no reads while rewriting.
Has anyone encountered such problems?</div>
<div>To replicate the issue is is possidle to run fio twice with the same configuration to achieve rewriting or to run iozone. Both tools return similar outputs.</div>
<div><span>
<pre>-- <br></pre>
<div style="font-size: 9pt; color: rgb(89, 89, 89); font-family: verdana;">S přáním pěkného dne / Best regards</div>
<br style="caret-color: rgb(46, 52, 54); color: rgb(46, 52, 54);">
<div style="font-size: 11pt; color: rgb(220, 38, 30); font-family: verdana;"><b>Mgr. Peter Hruška</b><br>
</div>
<div style="font-size: 9pt; font-family: verdana;"><font color="#595959">IT specialista</font><br>
<br>
<div style="font-size: 9pt;"><span style="color: rgb(89, 89, 89); font-size: 9pt; font-family: Verdana, sans-serif;"><b>M Computers s.r.o.</b><br>
</span><span style="color: rgb(220, 38, 30); font-size: 9pt; font-family: Verdana, sans-serif;">Úlehlova 3100/10, 628 00 Brno-Líšeň (<a href="https://mapy.cz/s/gafufehufe" title="Click to open https://mapy.cz/s/gafufehufe" style="color: rgb(149, 79, 114);"><span style="color: rgb(5, 99, 193);">mapa</span></a>)</span><span style="font-size: 9pt; font-family: Verdana, sans-serif;"><br>
<font color="#595959">T:+420 515 538 136</font><br>
<font color="#595959">E: </font></span><a href="mailto:peter.hruska@mcomputers.cz" title="Click to mail peter.hruska@mcomputers.cz" style="font-size: 9pt; color: rgb(149, 79, 114); font-family: Verdana, sans-serif;"><span style="color: rgb(5, 99, 193);">peter.hruska@mcomputers.cz</span></a><span style="font-size: 9pt; font-family: Verdana, sans-serif;"><font color="#595959"><br>
</font><font color="#0563c1"><span style="caret-color: rgb(5, 99, 193);"></span></font></span><span style="font-size: 9pt; font-family: Verdana, sans-serif;"><br>
<a href="http://www.mcomputers.cz/" title="Click to open http://www.mcomputers.cz/" style="color: rgb(149, 79, 114);"><span style="color: rgb(5, 99, 193);">www.mcomputers.cz</span></a><br>
</span></div>
</div>
<div><a href="http://www.lenovoshop.cz/" title="Click to open http://www.lenovoshop.cz/" style="font-family: Verdana, sans-serif; font-size: 9pt;">www.lenovoshop.cz</a></div>
<div><img src="cid:d720b14ac4f99022ef331403ba1fb9d89b0f0d64.camel@mcomputers.cz-0" width="457px" height="106px"></div>
<div style="font-size : 9pt; color:#595959;
font-family : verdana"></div>
<div style="font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-tap-highlight-color: rgba(0, 0, 0, 0.4); -webkit-text-stroke-width: 0px; text-decoration: none; font-size: 9pt; color: rgb(89, 89, 89); font-family: verdana;">
<br>
</div>
<div style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Cantarell; font-size: 14.666666984558105px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-tap-highlight-color: rgba(0, 0, 0, 0.4); -webkit-text-stroke-width: 0px; text-decoration: none;">
<br>
</div>
</span></div>
</body>
</html>