[ceph-users] Bareos and libradosstriper works only for 4M sripe_unit size

Alexander Kushnirenko kushnirenko at gmail.com
Wed Oct 11 05:19:49 PDT 2017


Oh!  I put a wrong link, sorry  The picture which explains stripe_unit and
stripe count is here:

https://indico.cern.ch/event/330212/contributions/1718786/attachments/642384/883834/CephPluginForXroot.pdf

I tried to attach it in the mail, but it was blocked.


On Wed, Oct 11, 2017 at 3:16 PM, Alexander Kushnirenko <
kushnirenko at gmail.com> wrote:

> Hi, Ian!
>
> Thank you for your reference!
>
> Could you comment on the following rule:
> object_size = stripe_unit * stripe_count
> Or it is not necessarily so?
>
> I refer to page 8 in this report:
>
> https://indico.cern.ch/event/531810/contributions/2298934/at
> tachments/1358128/2053937/Ceph-Experience-at-RAL-final.pdf
>
>
> Alexander.
>
> On Wed, Oct 11, 2017 at 1:11 PM, <ian.johnson at stfc.ac.uk> wrote:
>
>> Hi Gregory
>>
>> You’re right, when setting the object layout in libradosstriper, one
>> should set all three parameters (the number of stripes, the size of the
>> stripe unit, and the size of the striped object). The Ceph plugin for
>> GridFTP has an example of this at https://github.com/stfc/gridFT
>> PCephPlugin/blob/master/ceph_posix.cpp#L371
>>
>>
>>
>> At RAL, we use the following values:
>>
>>
>>
>> $STRIPER_NUM_STRIPES 1
>>
>> $STRIPER_STRIPE_UNIT 8388608
>>
>> $STRIPER_OBJECT_SIZE 67108864
>>
>>
>>
>> Regards,
>>
>>
>>
>> Ian Johnson MBCS
>>
>> Data Services Group
>>
>> Scientific Computing Department
>>
>> Rutherford Appleton Laboratory
>>
>>
>>
>> _______________________________________________
>> ceph-users mailing list
>> ceph-users at lists.ceph.com
>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>>
>>
>
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