CMS Tier-2 resource management

The Tier-2 centers in CMS are the only location, besides the specialized analysis facility at CERN, where users are able to obtain guaranteed access to CMS data samples. The Tier-1 centers are used primarily for organized processing and storage. The Tier-1s are specified with data export and network capacity to allow the Tier-2 centers to refresh the data in disk storage regularly for analysis. A nominal Tier-2 center will deploy 200 TeraBytes of storage for CMS. The CMS expectation for the global Tier-2 capacity is more than 5 PB of useable disk storage. In order to manage such a large and highly distributed resource CMS has tried to introduce policy and structure to the Tier-2 storage and processing. In this presentation I discuss the CMS policy for dividing resources between the local community, the individual users, CMS centrally, and focused CMS analysis groups. I focus on the technical challenges associated with management and accounting as well as the collaborative challenges of assigning resources to the whole community. The different challenges associated with partitioning dynamic resources like processing and more static resources like storage will be explored. I show the level of dynamic data placement and resource utilization achieved and the level of distribution CMS expects to achieve in the future