Dear PEB Member

The following is a proposal to establish a short term group of experts to define the services that a Tier 2 centre will require from a Tier 1 centre. This is needed to ensure that the MoU Task Force is fully informed of the responsibilities of Tier 1 centres and to assist Tier 2 centres, particularly those in countries with no Tier 1, in their planning. It is also needed to provide background information for negotiations between CERN and countries that assume that CERN will provide such services.

I would like to discuss this at the PEB next week.

Regards, Les

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Tier 1 services for Tier 2 centres

The current management and organisational model for the LCG computing grid assumes that Tier 2 centres receive certain services from Tier 1 centres. These could include:

In some case such services will be provided by national Tier 1 centres, but in many cases it will be necessary for Tier 2 centres to negotiate this support from Tier 1 centres in other countries. A Task Force has been established to elaborate the LHC Computing MoU. This will cover at least the Tier 0 and Tier 1 centres, and so it is necessary now to begin to define the services that Tier 1 centres must provide for Tier 2s. At the same time a number of Tier 2 centres are developing their plans, which must include identifying and negotiating the services they require from Tier 1. 
 
A small group** is at present working on a re-assessment of the computing resources required by the LHC experiments from 2006 onwards at Tier 1 and Tier 2 centres, to inform the Computing MoU Task Force.
 
I would now like to appoint a small group of experts to produce a description of the services that will be required by a Tier 2 centres from a Tier 1, to further inform the MoU Task Force, and as information for people planning Tier 2 centres. The group should start work as soon as the report on computing resources is available - scheduled for mid-April. The target would be to report by mid-June. I propose that this group consist of four experts, two from Tier 2 centres and two from Tier 1 centres. These would preferably be people that have been studying the issue of Tier 1 - Tier 2 support, should include someone from FZK, which has been discussing such support with other countries. 
 
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** Resource re-assessment group: ALICE - Alberto Masoni, ATLAS - Dario Barberis, CMS - David Stickland, LHCb - Nick Brook, Fabric Manager - Bernd Panzer, Networking - David Foster, LCG Resource Manager - Chris Eck, chair - Les Robertson.