11/5/2001WP5 UKHEPGRID1 WP5 Mass Storage UK HEPGrid UCL 11th May Tim Folkes, RAL

11/5/2001WP5 UKHEPGRID2 Tasks Review and evaluate current technologies A common API to heterogeneous MSS Tape exchange, including metadata Metadata publishing

11/5/2001WP5 UKHEPGRID3 Common API Defines an API which can be used by Grid middle ware to interface to MSS Side effect of making user programmes portable as well Original scheme has changed due to ATF activity

11/5/2001WP5 UKHEPGRID4 Pre ATF Mass storage was treated as local Just tape storage No need to handle grid proxies etc WP2 datamover, replication manager etc would handle this We would define an API like RFIO and testbeds would implement locally

11/5/2001WP5 UKHEPGRID5 ATF Concept of Grid storage Defined a StorageElement (SE) that includes direct access from the Grid Access to disk and tape (i.e. all storage, and the management of the disk space)

11/5/2001WP5 UKHEPGRID6 ATF 3 interfaces defined –put/get –open/read –management Move from files to objects Required a rethink, need software not just API

11/5/2001WP5 UKHEPGRID7 ATF - What to do? Evaluate Castor –Stripped down version for disk management –At RAL for use on datastore GridFTP for data transfer GridFTP server as SE

11/5/2001WP5 UKHEPGRID8 GridFTP Globus have reworked their I/O plans GridFTP basis of future data movement –tuneable for network performance –parallel streams –third party transfers, partial file transfer –file and stream interfaces RAL and CERN have tested alpha code –but just for transfer

11/5/2001WP5 UKHEPGRID9 GridFTP server as SE Looks feasible given GASS experience to implement SE using GridFTP server Uses globus infrastructure Handles GSI proxies Gives trivial access to local disk and any HSM with Unix filestore interface Plan to produce prototype for M9 for Unix filesystem and Castor

11/5/2001WP5 UKHEPGRID10 Task 2 If networks don’t deliver, may have to move data by tape between CERN and Regional centres May be easier to take tape out of robot and move, rather than copy ANSI standard that covers this Will investigate this and implement if suitable

11/5/2001WP5 UKHEPGRID11 Task 3 Metadata Provide metadata about SE and its contents, not about data itself Require somewhere to publish static information Require support for acting as active publisher of dynamic metadata Still require input from other WP’s on what information they require

11/5/2001WP5 UKHEPGRID12 Deliverables WP5 will deliver software for - –data access –metadata production Provide SE interface based on GrifFTP server –Support for castor and Unix filesystem and access by ReplicaManager at M9

11/5/2001WP5 UKHEPGRID13 Future Developments User API to allow direct user access to remote data SE on other HSMs Disk housekeeping as part of SE Management interface to SE (create, stage, reserve, pinning….)