Eduardo: Looks like you have uncovered a bug. So far, we have found the problem as far back as 2.8.4. We are still investigating and will keep you posted.
thanks! Becky Ligon On Tue, Sep 6, 2016 at 3:34 PM, Eduardo CAMILO Inacio < [email protected]> wrote: > Dear PVFS2 users, > > After performing some experiments on OrangeFS 2.8.8, I am a little > confused about the default distribution layout. Systems manual, change log, > and some published papers claim that it should be ROUND_ROBIN. By that, I > understand that a server is randomly chosen to store the first 64 KB of the > file, and the second 64 KB block would be stored in the next server > according to the order in the configuration file, and so on. > > In my experiments, what I am observing is more close to the behavior I > would expect with a RANDOM layout. For instance, when two out of four > servers are chosen to store objects from a file, independently if the > "user.pvfs2.num_dfiles" is set to 2 or if the file size is just 2x the > stripe size, it seems like the two servers are being chosen randomly. > > It is worth noting that no change was performed in the generated config > file; the number of data files is changed through setfattr commands before > experiments. POSIX requests are being generated using the IOR benchmark > v3.0.1 with MPICH 3.2, which, I am assuming, is not changing the layout of > the file system. > > Attached, you will find some output that illustrate the aforementioned > behavior. > > Any insight on this subject would be helpful. > > Best, > -- > Eduardo Camilo Inacio > > _______________________________________________ > Pvfs2-users mailing list > [email protected] > http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users > >
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