Thank your all for your advice! I'll try that next week and get back to you if I have questions.
Matthieu ----- Mail original ----- > De: "Becky Ligon" <[email protected]> > À: "Kyle Schochenmaier" <[email protected]> > Cc: "Matthieu Dorier" <[email protected]>, "pvfs2-users" > <[email protected]> > Envoyé: Lundi 11 Février 2013 23:59:56 > Objet: Re: [Pvfs2-users] Using PVFS2's API directly > Matthieu: > If you are using OrangeFS 2.8.7, then you can use the pvfs usr > library. The library calls are the preferred way to directly call > the filesystem. Please take a look at > http://www.orangefs.org/trac/orangefs/wiki/Posix-like%20APIs . This > wiki page will describe how to get started with the usr library. > If you have questions, feel free to write back. > Becky > On Thu, Feb 7, 2013 at 11:53 AM, Becky Ligon < [email protected] > > wrote: > > Matthieu: > > > Look at the Orangefs.org wiki page on distributions and layouts. > > This > > page describes how you can specify the different options when > > creating a file using the API. ( > > http://www.orangefs.org/trac/orangefs/wiki/Distributions ) > > > Becky > > > On Thu, Feb 7, 2013 at 11:37 AM, Kyle Schochenmaier < > > [email protected] > wrote: > > > > Hi Mattieu - > > > > > > I'm not sure if a 0 size will work, in fact, if it wasnt designed > > > in > > > it may crash things (I havent looked at this distribution's code > > > in > > > years). > > > > > > Moreover, the server numbers you're seeing in the example are the > > > servers in the 'stripe' but may not correspond to the logical > > > server > > > numbers that you're thinking of. > > > > > > This is because the '0th' server in the stripe is determined > > > randomly > > > among the set of servers in the filesystem and intentionally > > > changes > > > so as to avoid hitting the same server repeatedly for every file > > > creation, or in the case of many small files that dont fill an > > > entire stripe this prevents uneven distribution of the file > > > handles. > > > > > > Regards, > > > > > > ~Kyle > > > > > > Kyle Schochenmaier > > > > > > On Thu, Feb 7, 2013 at 10:30 AM, Matthieu Dorier < > > > [email protected] > wrote: > > > > > > > Hi Kyle, > > > > > > > > > > Thank you for the advice, these codes should be indeed a good > > > > place > > > > to start. > > > > > > > > > > Regarding the distribution, I dug a bit and found here > > > > http://www.orangefs.org/doxygen/index.html some functions to > > > > set/get > > > > extended attributes (e.g. pvfs_fsetxattr) . Then at > > > > http://www.pvfs.org/cvs/pvfs-2-8-branch-docs/doc/pvfs2-tuning/pvfs2-tuning.html > > > > in section 7.4 I see a way to set the stripe size on a > > > > per-server > > > > basis so I guess I could put 0 for the servers I don't want to > > > > use > > > > and a positive value for the servers I want to use. Would that > > > > work? > > > > > > > > > > Thanks, > > > > > > > > > > Matthieu > > > > > > > > > > > De: "Kyle Schochenmaier" < [email protected] > > > > > > > > > > > > > > > > À: "Matthieu Dorier" < [email protected] > > > > > > > > > > > > > > > > Cc: "pvfs2-users" < [email protected] > > > > > > > > > > > > > > > > Envoyé: Jeudi 7 Février 2013 17:05:06 > > > > > > > > > > > > > > > Objet: Re: [Pvfs2-users] Using PVFS2's API directly > > > > > > > > > > > > > > > Hi Matthieu - > > > > > > > > > > > > > > > For API examples I would start with looking at the admin > > > > > tools > > > > > like > > > > > pvfs2-cp, etc as they utilize the libpvfs apis directly. > > > > > > > > > > > > > > > I'm not sure if you're able to specify any of the information > > > > > you > > > > > want to on a per-file basis at creation time. > > > > > > > > > > > > > > > This information is pulled in from the distribution params of > > > > > the > > > > > directory the file is created in. There may be other methods > > > > > I'm > > > > > not > > > > > immediately thinking of though... I'll let others comment. > > > > > > > > > > > > > > > ~Kyle > > > > > > > > > > > > > > > Kyle Schochenmaier > > > > > > > > > > > > > > > On Thu, Feb 7, 2013 at 7:05 AM, Matthieu Dorier < > > > > > [email protected] > wrote: > > > > > > > > > > > > > > > > Hi, > > > > > > > > > > > > > > > > > > > > > I would like to use the client API provided by PVFS2, > > > > > > without > > > > > > any > > > > > > kernel support or MPI-I/O interface. Where can I find > > > > > > documentation > > > > > > and code samples of this API? > > > > > > > > > > > > > > > > > > > > > Also I'd like to know if there is a way to specify, when > > > > > > creating > > > > > > a > > > > > > file (so from within a client application), the list of > > > > > > storage > > > > > > servers to which this file should go and the stripe size, > > > > > > in > > > > > > order > > > > > > to bypass the configuration of the directory in which the > > > > > > file > > > > > > is > > > > > > created? > > > > > > > > > > > > > > > > > > > > > Thanks! > > > > > > > > > > > > > > > > > > > > > Matthieu Dorier > > > > > > > > > > > > > > > > > > > > > PhD student at ENS Cachan Brittany and IRISA > > > > > > > > > > > > > > > > > > > > > http://people.irisa.fr/Matthieu.Dorier > > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > > > > > > > > > > > > > > > > Pvfs2-users mailing list > > > > > > > > > > > > > > > > > > > > > [email protected] > > > > > > > > > > > > > > > > > > > > > http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > Pvfs2-users mailing list > > > > > > [email protected] > > > > > > http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users > > > > > -- > > > Becky Ligon > > > OrangeFS Support and Development > > > Omnibond Systems > > > Anderson, South Carolina > > -- > Becky Ligon > OrangeFS Support and Development > Omnibond Systems > Anderson, South Carolina
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