The SRM Protocol GSM-WG Jens Jensen OGF 23, Barcelona

Background • SRM is the

Storage Resource Manager

• A

Control protocol

for Mass Storage Systems • Standard protocol: OGF GSM-WG • Used by WLCG (OSG, EGEE, ...),

Storage Element Implementations • dCache (DESY+FNAL) • DPM (CERN) • CASTOR (CERN+STFC/RAL) • BestMan (LBNL) • Jasmine (JLAB) • StoRM (ICTP-EGRID+INFN)

What is a “Storage Element”?

• Computing • Data Mgmt Metadata THE (gLite) GRID Storage Element Tape storage Disk storage Disk storage Disk storage Disk Pools

What is a “Storage Element” • Interface to mass storage systems • Part of a loosely coupled grid • Provide uniform (control) interface • Protect the storage system against the grid • Enable grid to efficiently use storage

What is a Storage Element?

Used by EGEE, OSG,… Six-seven different implementations Storage Element Information System Control Interface (SRM) Data Transfer An SRM is a “Storage Element” but not vice versa GIN: Use SRB as Storage Element

Tech • ~6 interoperating implementations – 362 storage elements deployed – 226 are SRM1 implementations – 6 SRM2 implementations (can’t be quite right) • Some Open Source, some not • Using SOAP over GSI sockets – Delegation needed for srmCopy – No WS-Anything

LFN Where is the File LFN LFN GUID SURL Physical File SURL Physical File SURL TURL Physical File Storage Elements

Information View (simplified) Storage Element Owner/ Access VOInfo Control Protocol Data Transfer Protocol Storage Area Space?

Resource Accounting

Transfer Protocols • WAN protocols – Must always support GridFTP – Suggestion to support HTTP/HTTPS • GSI issue though - see tech slide • dCache supports http for reading • Support LAN protocols – Secure vs insecure

LCG: GFAL • LCG (will) decide to use GFAL – the “Grid File Access Library ” • It was decided to interface to EDG SE using SRM 1 interface • For now using EDG RM POSIX interface SRM 1 client EDG SRM EDG 2.1 Storage Element Mass Storage

EGEE: DICOM server support The Grid Metadata Metadata Storage Element Store patient metadata Store key Access control on metadata required; different ACLs for different types of metadata WP10 DM2 Encrypt, anonymise DICOM Server