Padova, 5 October StoRM Service view Riccardo Zappi INFN-CNAF Bologna

Padova, 5 OctoberStorage Task Force Meeting Page 2 Outline Forewords –SNIA – SSM Model –Storage System example –Storage Element What SRM and StoRM are Aggregation within Application layer (difference with DPM and dCache) StoRM feasible tests Storage resource access scenario with StoRM

Padova, 5 OctoberStorage Task Force Meeting Page 3 Storage domain The SNIA–SSM: Shared Storage Model Application File/record layer Database (dbms) File system (fs) Block layer Storage devices (disks, …) Block aggregation Host Network Device Services Discovery, monitoring Resource mgmt, configuration Security, billing Redundancy mgmt (backup, …) High availability (fail-over, …) High availability (fail-over, …) Capacity planning Mgmt Client SMIS

Padova, 5 OctoberStorage Task Force Meeting Page 4 Device block-aggregation Network block-aggregation Host block-aggregation Clustering inter-box aggregation (example) File/record layer Block layer Host NAS head Host Disk array SN NAS head LAN Cluster FS Purposes: load spreading across peers (scalability) alternate paths (high availability, scalability) Purposes: load spreading across peers (scalability) alternate paths (high availability, scalability) Application GPFSLustre

Padova, 5 OctoberStorage Task Force Meeting Page 5 File/record layer Block layer Host Application LAN File metadata NAS head Files Aggregation metadata NAS head Aggregation within Application layer DPM - No cluster-FS. dCache - Hierarchical MSS

Padova, 5 OctoberStorage Task Force Meeting Page 6 Grid Storage Element Storage Element (SE) represents a storage system abstraction in Grid.

Padova, 5 OctoberStorage Task Force Meeting Page 7 SRM : Storage Mgmt Middleware within the Grid Storage Resource Managers (SRMs) SRMs are middleware components that manage shared storage resources on the grid and provide management functionalities like: –Uniform access to heterogeneous types of storage –File pinning –Disk space allocation and advanced disk space reservation –Protocol negotiation –Life time management of files –Management of security SRMs implements a SRM interface specified by GSM-WG within GGF. (v.1.1, v and v.3.0)

Padova, 5 OctoberStorage Task Force Meeting Page 8 Managent Access & Data Access to SE

Padova, 5 OctoberStorage Task Force Meeting Page 9 What StoRM is StoRM is a Storage Resource Manager. It is exposed as web service. –Web service description (wsdl) of StoRM is compliant with SRM specification version StoRM prefers Cluster File System with ACL support. Current StoRM version is built on top of GPFS (Plugin for Lustre FS is coming soon). StoRM allows direct access (native posix call) [i.e. StoRM works without server I/O too]. Aggregation is performed by underlying file system (better than StoRM could do).

Padova, 5 OctoberStorage Task Force Meeting Page 10 Feasible tests on Grid Storage System Storage System Tests on underlying Storage System with different Hardware/Software configurations. Storage Services Data Access by Jobs running in WNs. Data Transfer by Transfer Service. Management calls by jobs, services, clients. Information provider… ( ? )

Padova, 5 OctoberStorage Task Force Meeting Page 11 StoRM (SRM) test StoRM is a management service. StoRM is not a I/O service. TESTs Functionality tests –Well/Bad formed function call test –SRM interface compliance test –Security hacking Stress tests –Bombing with well/bad formed function calls –Huge size requests Integration test –Use of SRM by other Service (FTS, Agreement Service, …) –Use of SRM with other Service (LCMAPS, PBox, etc, … ) Failure test (network crash, database crash, power crash,..) Perverse test

Padova, 5 OctoberStorage Task Force Meeting Page 12 StoRM test environment Test bed #1 (V.Vagnoni) [build] 1.Only StoRM ahead of Storage System based on GPFS. –Useful for [ Functionality, Stress, Failure ] tests Test bed #2 (Certification INFN-Grid) [finishing] 1.Storage Element (GridFTP server, LCMAPS, StoRM, Authorization service (PBox), ecc.. ) 2.Computing Element and some work nodes. –Useful for [ Integration / Stress / Failure ] tests Test bed #3 (Certification INFN-Grid) [coming soon] 1.Nr.2 (or more) Test bed #2 2.External Service (FTS, LFC / FireMan, … ) –Useful for [ Integration / Failure / Perverse ]

Padova, 5 OctoberStorage Task Force Meeting Page 13

Padova, 5 October StoRM use cases Backup splides

Padova, 5 OctoberStorage Task Force Meeting Page 15 Storage Element Computing Element and WNs

Padova, 5 OctoberStorage Task Force Meeting Page 16 References DMTF SNIA SMI-S GPFS LUSTRE SRM