Hi,

Thankyou for your comments. Please see one response from me embedded below.

Also, does dcache too have the limitation of 2TB per filesystem (perhaps 
I got all wrong?)

Thank you again for patiently going through my questions.
Nagaraj

Steve Traylen wrote:

>On Thu, Dec 15, 2005 at 06:19:44AM +0530 or thereabouts, P. Nagaraj wrote:
>  
>
>>Dear experts,
>>
>>We plan to increase storage capacity of our site. To begin 
>>with, by a few tens of TB, in the form of RAID arrays. 
>>And we are faced with some questions.
>>
>>With the limitations on filesystem sizes, what are the good options of 
>>deploying larger storage? Vendors do have proprietary 
>>solutions which are expensive - but there must be other options used by 
>>the LCG community.
>>    
>>
>
>The solutions of numerous within LCG.
>
>Two that are widely deployed are dCache and DPM which both
>do disk pool management, comments on their comparison at
>https://wiki.gridpp.ac.uk/wiki/Which_SRM
>
>If you are after a real filesystem across your storage blocks 
>with grid interfaces on top of that then the GFS and StoRM looks
>to be potentially very good.
>
>  
>
>>How many filesystems can the LCG software of an SE handle? How many SE's 
>>can a site have? 
>>    
>>
>
>A file system per VO is the obvious and easiest to deploy. Though you
>could just publish each partition as a seperate SARoot but this is difficult
>to use since then end user has to make so many decisions how where
>he might want to put his data.
>  
>
>>If we have storage devices of different i/o rates (like disks 15k 
>>rpm/7200rpm ) how could we best use them? 
>>
>>Is there a way to separately store  the input of WN's from output?
>>    
>>
>
>Sorry, I don't understand the question?
>  
>
My query was: Is there a way to arrange input data for WN's on a 
different filesystem, and make the WN output go to another one?
Is there a purpose in having a large filesystem made available to the 
WN's by NFS? What could such a filesystem best have on it (for example, 
some common data needed by many WN's?)
Or is it always better to have the entire input and out sandboxes on the 
WN's local filesystem?


>>Also, we request sites that have already deployed large storages to help 
>>us with their experiences.
>>    
>>
>
>All the experience of the UK storage deployment is probably linked with
>the wiki pages above.
>  
>
>>Thank you.
>>Nagaraj
>>  
>>
>>
>>+----------------------------------+--------------------------------------+
>>Nagaraj Panyam                     | Office tel: +91-22-22782610
>>Dept of High Energy Physics        | Office fax: +91-22-22804610 
>>Tata Instt. of Fundamental Research| Home  tel : +91-22-22804936        
>>Mumbai - 400 005, INDIA            | **Email** : [log in to unmask]          
>>+----------------------------------+--------------------------------------+
>>    
>>
>
>  
>


-- 

+----------------------------------+--------------------------------------+
Nagaraj Panyam                     | Office tel: +91-22-22782610
Dept of High Energy Physics        | Office fax: +91-22-22804610 
Tata Instt. of Fundamental Research| Home  tel : +91-22-22804936        
Mumbai - 400 005, INDIA            | **Email** : [log in to unmask]          
+----------------------------------+--------------------------------------+