[lustre-discuss] question about /proc/fs/lustre/osc/ and llapi functions.

[John Bauer]

Andreas

First, thanks for the response.  Second,  I looked at that at one time, 
seeming the logical answer, but I must have misread/mistyped something.  
My apologies.

Thanks gain
John

On 4/12/2017 3:34 AM, Dilger, Andreas wrote:
> On Apr 7, 2017, at 18:06, John Bauer <bauerj at iodoctors.com> wrote:
>> In /proc/fs/lustre/osc/ is an entry for every osc of all the lustre files systems on a client node of the form nbp9-OST0124-osc-ffff880ffaa4bc00
>>
>> My I/O instrumentation library tracks OSC's associated with an application file by reading the files in the directory for each OSC the application file is striped on.
>> I am trying to avoid the use of opendir() and readdir() to find the OSC entry of interest as there are 1284 entries in the lustre/osc directory, and I do this for hundreds of application files on hundreds of ranks.
>> I would like to generated the names of the osc entries I need, on the fly, given the discoverable file system name and osc indices.
>>
>> I can find the file system name, nbp9, with llapi_getname().  I can generate the OSTxxxx part with the osc index from llapi_get_stripe().
>> My question is, where do I find the ffff880ffaa4bc00 that is part of the directory entry for each OSC?  The value would appear to be file system
>> related, as each OSC associated with a given file system has the same value.  OSC's of a different file system have a different value. Is there an llapi_xxxx() call that will get me this value.
>
> There is llapi_getname() which will return the fsname and the instance identifier.
>
> Cheers, Andreas
> --
> Andreas Dilger
> Lustre Principal Architect
> Intel Corporation
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