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Mihael Hategan wrote:
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<pre wrap="">On Mon, 2008-12-01 at 16:52 -0600, Ioan Raicu wrote:
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<pre wrap="">...
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<pre wrap="">I don't think you realize how expensive GPFS access is when doing so
at 100K CPU scale.
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I don't think I understand what you mean by "access". As I said, things
that generate contention are going to be slow.
If the problem requires that contention to happen, then it doesn't
matter what the solution is. If it does not, then I suspect that there
is a way to avoid contention in GPFS, too (sticking things in different
directories).
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The basic idea is that many smaller shared file systems will scale
better than 1 large file system, as the contention is localized. The
problem is that having 1 global namespace is simple and straight
forward, but having N local namespaces is not, and requires extra
management. If we try to beat GPFS by implementing a global
shared/parallel file system, we are likely to fail, as Ben or you
already mentioned... but by changing the landscape a bit by splitting
the single large global space into many smaller spaces, we should gain
scalability and performance larger scales.<br>
<br>
Ioan<br>
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<pre class="moz-signature" cols="72">--
===================================================
Ioan Raicu
Ph.D. Candidate
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Distributed Systems Laboratory
Computer Science Department
University of Chicago
1100 E. 58th Street, Ryerson Hall
Chicago, IL 60637
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Email: <a class="moz-txt-link-abbreviated" href="mailto:iraicu@cs.uchicago.edu">iraicu@cs.uchicago.edu</a>
Web: <a class="moz-txt-link-freetext" href="http://www.cs.uchicago.edu/~iraicu">http://www.cs.uchicago.edu/~iraicu</a>
<a class="moz-txt-link-freetext" href="http://dev.globus.org/wiki/Incubator/Falkon">http://dev.globus.org/wiki/Incubator/Falkon</a>
<a class="moz-txt-link-freetext" href="http://dsl-wiki.cs.uchicago.edu/index.php/Main_Page">http://dsl-wiki.cs.uchicago.edu/index.php/Main_Page</a>
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