Introduction

This page briefly explains what the ATLAS computing model is, what facilities are avaliable at RAL and how ATLAS users can access them.

The ATLAS computing Model

Tier 0 This is CERN where the raw data will be produced. This is archived at CERN before being distributed to the Tier 1s.

Tier 1 There are 10 Tier 1s serving ATLAS. RAL is the UK Tier 1 and is expected to recieve 10% of the raw data from CERN. Tier 1

Tier 2

Tier 3

This page explains the computing model and the hardware that is avaliable at RAL.

Tier 1

The Tier 1 for the UK cloud is based at RAL. The Tier 1 is in the machine room in building R89.

In order to run at the Tier 1 you grid certificate must be either: /atlas/uk/Role=production /atlas/uk/Role=poweruser0

Tier 2

As well as the Tier 1 there is a Tier 2 cluster also based at RAL however it is in a different building from the Tier 1 and run by different people.

Tier 3

The Tier 3 is actually part of the Tier 2 that has been reserved for use by RAL staff.

-- AlastairDewhurst - 2009-10-09