In progress - starting with ATLAS requirements. Other experiments / storage systems should add material. See also pre-GDB talks for information that could be used to fill these tables https://indico.cern.ch/event/319817/

Current data access features required by WLCG experiments and the protocols used to provide

Feature	ATLAS
	Current	Proposed
Transfer and data access
Upload a complete file (From WN -> Storage)	SRM +gridFTP/Xrootd	gridFTP, xrootd
Download complete file (From Storage -> WN or user machine)	ZOO (rfio, dcap,http, xrootd, gridFTP, SRM)	Xrootd, file, gridFTP, http
Direct access of file (From Storage on WN)	Dcap,xrootd, file, rfio	Xrootd, File, (maybe http (davix))
Manage third-party copy (FTS)	SRM + gridFTP	gridFTP-only
Namespace Interaction
Upload and check data integrity information (chksums)	gridFTP / xrootd (some servers)	gridFTP / xrootd/http (gfal2)
Deleting data and directories	SRM	WebDav
Changing ownership, perms and ACLs	SRM (Or admin)	Site Admin?
Storage Capacity Management
Query used capacity (like df)	SRM	WebDav or JSON file
Targeting uploads to specific reservation	SRM	Just namespace

Support for Protocols by Storage Systems in use by WLCG

Guidance (links and resources) for sites wanting to deploy storage for WLCG experiments or change from one protocol to another

-- WahidBhimji - 2015-01-21