[Gluster-users] disperse volume and its relation to xlators/cluster/ec

[jayakrishnan mm]

Dear  Xavi,

  How  is  the  data fragmented ? what if  a file  size  is  more than  the
fragment size? Can a fragment have data corresponding to 2 or more files ?
  How  the  data is  accessed  basically ( file open ?) ?  What  is  a
frame ?
  I have  searched a lot  of  documents about  glusterFS. None  of these
are  helpful  to understand  the  glusterFS in detail (from the perspective
of  writing  a  new translator),
  Jeff Darcy's tutorial  was helpful though.
   Perhaps, am I missing something?

  Can you  point to some good stuffs ?

Best Regards
JK

On Wed, Feb 17, 2016 at 4:24 PM, jayakrishnan mm <jayakrishnan.mm at gmail.com>
wrote:

> Dear Xavi,
>
> Thanks  a lot. That clarified my confusion.
>
> Best Regards
> JK
>
> On Wed, Feb 17, 2016 at 3:35 PM, Xavier Hernandez <xhernandez at datalab.es>
> wrote:
>
>> Hi jayakrishnan,
>>
>> the old implementation was not finally accepted to be included in main
>> glusterfs tree, so it was rewritten in what now is known as ec.
>>
>> disperse is an alias for ec. They are the same. The algorithm implemented
>> is Reed-Solomon. It's really similar to ida (we could say that ida is a
>> specific implementation of a Reed-Solomon code).
>>
>> Almost all basic functionality in old code is implemented in new ec in
>> some way, though not using the same approaches. Anyway the latest
>> implementation is way more stable and maintained, while the old code has
>> been abandoned and should not be used.
>>
>> Regards,
>>
>> Xavi
>>
>>
>> On 17/02/16 05:12, jayakrishnan mm wrote:
>>
>>> Dear  Xavier,
>>>
>>> I am trying to understand the disperse  translator  and its  usage.
>>>
>>>  From
>>>
>>> https://lists.gnu.org/archive/html/gluster-devel/2014-01/txttzloLYIJOh.txt
>>> , I see  there  are  four  components namely gfsys,dfc,ida  and  heal
>>> which needs  to  be  compiled  with GlusterFS main source code.
>>> I am  confused  this with xlator/cluster/ec.   What is the relationship
>>> between this  and  the disperse volume components  mentioned  earlier ?
>>>   Is   xlator/cluster/ec  is  erasure coding (ec) translator
>>> implementation  in glusterFS ? If yes, which algorithm it implements ? (
>>> I know  disperse  volume implements IDA)
>>> Pls. help
>>>
>>> Best Regards
>>> JK
>>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.gluster.org/pipermail/gluster-users/attachments/20160225/412c9b12/attachment.html>