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.htmlin
>>  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
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