Scalla: Extended Features Supplement

Migration-Purge-Staging Support

MPS Reference

Andrew Hanushevsky

Stanford Linear Accelerator Center

1-February-2008

Acknowledgments

The MPS system was designed by Andrew Hanushevsky and Bill Weeks

mps_MigrPurg and mps_PreStage were designed and developed by Bill Weeks

mps_Stage and mps_Xeq were designed and developed by Andrew Hanushevsky

mps_prep was designed by Andrew Hanushevsky and developed by Bill Weeks

All work was done for Stanford University under contract DE-AC02-76-SFO0515 with the Department of Energy

1 Introduction. 5

1.1 MPS Components 5

1.2 Related Components 8

2 mps_MigrPurg Command for Migration. 9

2.1 Modifying Migrate Policy via Priority Requests 13

3 mps_MigrPurg Command for Purging. 15

3.1 Modifying Purge Policy With Pin Files 21

3.2 Modifying Purge Policy via Priority Purge 21

4 mps_PreStage Command. 22

4.1 The mps_prep Command for the Prestage Queue 27

4.1.1 The Pre-Stage Request Queue. 31

5 mps_Stage Command. 33

6 mps_Xeq Command. 39

7 MPS Configuration. 45

7.1 Common Configuration Directives 49

7.2 Migration Specific Directives 55

7.3 Prestage Specific Directives 57

7.4 Purge Specific Directives 59

7.5 Staging Specific Directives 63

8 Interfacing an MSS. 71

8.1 msscmd mssstat Execution 72

8.2 ftpcmd Execution 73

8.3 xfrcmd Execution 75

9 Document Change History. 77

1 Introduction

This document describes Migration Purge Staging (MPS) commands and configuration directives. MPS was designed to enhanced support of the Open Storage System (oss) scalable file system, an xrootd extended feature. This feature is enabled when the Open File System (ofs) is loaded via libXrdOfs.so, at run-time using the xrootd.fslib configuration directive. MPS can be used to administer the local file system (i.e., placing fil