[Pvfs2-developers] Changing the number of I/O servers

[Christina Patrick]

Hi,

Does anybody have any idea why this is happening?

Thanks and Regards,
Christina.

On Tue, Jul 14, 2009 at 1:47 PM, Christina
Patrick<christina.subscribes at gmail.com> wrote:
> Hi Kevin,
>
> Yes, I am using mpich2-1.0.8 and pvfs2.8.0.
>
> Regards,
> Christina.
>
> On Tue, Jul 14, 2009 at 12:40 PM, Kevin Harms<harms at alcf.anl.gov> wrote:
>> Christina,
>>
>>  you are using MPICH2 and the ad_pvfs2 romio module?
>>
>> kevin
>>
>> On Jul 14, 2009, at 9:12 AM, Christina Patrick wrote:
>>
>>> Hi Everybody,
>>>
>>> I want to use MPI hints to create a striped file across a subset of
>>> the pvfs2 servers. For that I use, the hints "striping_unit" and
>>> "striping_factor". I have a set of three I/O servers. However, I want
>>> to create the file only on one I/O server. I specified "striping_unit"
>>> = 65536 and "striping_factor" = 1. However, after the file is created,
>>> I get the following results:
>>>
>>> pvfs2-viewdist -f /home/mdl/patrick/pvfs2/oneserver
>>> dist_name = simple_stripe
>>> dist_params:
>>> strip_size:65536
>>>
>>> Metadataserver: tcp://aum14:7000
>>> Number of datafiles/servers = 3
>>> Datafile 0 - tcp://aum15:7000, handle: 9223372036854775298
>>> (7ffffffffffffe02.bstream)
>>> Datafile 1 - tcp://aum13:7000, handle: 4611686018427387650
>>> (3fffffffffffff02.bstream)
>>> Datafile 2 - tcp://aum14:7000, handle: 4611686018427387905
>>> (4000000000000001.bstream)
>>>
>>> Am I missing something? I wanted to use this hint, so that I don't
>>> have to reconfigure the servers everytime, I want to change the number
>>> of I/O servers.
>>> Could somebody please help me?
>>>
>>> Thanks and Regards,
>>> Christina.
>>>
>>> PS: The extract from my program which does this:
>>>    79   MPI_Info_create(&file_info);
>>>    80
>>>    81   if(argc > 1) {
>>>    82     stripe_unit = atoi(argv[1]);
>>>    83     sprintf(stripe_unit_str, "%d", stripe_unit);
>>>    84     MPI_Info_set(file_info, "striping_unit", stripe_unit_str);
>>>    85   }
>>>    86
>>>    87   if(argc > 2) {
>>>    88     stripe_factor = atoi(argv[2]);
>>>    89     sprintf(stripe_factor_str, "%d", stripe_factor);
>>>    90     MPI_Info_set(file_info, "striping_factor", stripe_factor_str);
>>>    91   }
>>>    92
>>>    93   MPI_File_open(MPI_COMM_WORLD, fname, MPI_MODE_CREATE |
>>> MPI_MODE_WRONLY, file_info, &fhandle);
>>> _______________________________________________
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>>> Pvfs2-developers at beowulf-underground.org
>>> http://www.beowulf-underground.org/mailman/listinfo/pvfs2-developers
>>
>>
>