Gluster users - Jul 2014 - Does Gluster Support "Dynamic Configuration of Stripe count" ?

Hi ,

We are using GlusterFS in our product for DFS. We have  found an issue  
in using "striping" while experimenting with Striped Volumes in our
DFS
infrastructure. We thought of  enable striping to support "Max Files 
Size" when a file dynamically grows/shrink over time inside a brick. We 
need to add more storage dynamically to handle this situation and 
striped the file across bricks to fit it properly in that striped volume .

*Question*:  is  Does Gluster supports "dynamic configuration of Stripe 
Count" (increment / decrement  stripe count) of Striping currently  ?

We tried with following two  basic experiments :

1. Create a volume with two bricks with stripe count 2 with no replica ( 
to simplify ).

2. Add one more brick in that volume and increase stripe count by one ( 
the stripe count becomes 3 now) .
        - Seems it works  fine and files are being striped across 3 
bricks as per specified chunk-size .

3. However faced issues while removing a brick from the volume and 
decrement stripe count by one again ( so the stripe count becomes 2 again)
=> Gluster is  not allowing to reduce the stripe count in this scenario.

Could you please help us by clarifying this.

Thanks for your help

Regards,
Subrata Ghosh
(Ericsson  R&D)
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://supercolony.gluster.org/pipermail/gluster-users/attachments/20140722/e83f2a42/attachment.html>

Can you please help for  this. It is really becoming critical for us.

Regards,
Subrata


On 07/22/2014 04:45 PM, Subrata Ghosh wrote:
> Hi ,
>
> We are using GlusterFS in our product for DFS. We have  found an 
> issue  in using "striping" while experimenting with Striped
Volumes in
> our DFS infrastructure. We thought of  enable striping to support "Max
> Files Size" when a file dynamically grows/shrink over time inside a 
> brick. We need to add more storage dynamically to handle this 
> situation and striped the file across bricks to fit it properly in 
> that striped volume .
>
> *Question*:  is  Does Gluster supports "dynamic configuration of 
> Stripe Count" (increment / decrement  stripe count) of Striping  
> currently  ?
>
> We tried with following two  basic experiments :
>
> 1. Create a volume with two bricks with stripe count 2 with no replica 
> ( to simplify ).
>
> 2. Add one more brick in that volume and increase stripe count by one 
> ( the stripe count becomes 3 now) .
>        - Seems it works  fine and files are being striped across 3 
> bricks as per specified chunk-size .
>
> 3. However faced issues while removing a brick from the volume and 
> decrement stripe count by one again ( so the stripe count becomes 2 again)
>     => Gluster is  not allowing to reduce the stripe count in this 
> scenario.
>
> Could you please help us by clarifying this.
>
> Thanks for your help
>
> Regards,
> Subrata Ghosh
> (Ericsson  R&D) 
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://supercolony.gluster.org/pipermail/gluster-users/attachments/20140723/c9cb140f/attachment.html>