HP Hitachi Dynamic Link Manager Software - Manual (Page 15)

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Contents
Preface i
Intended Readers ........................................................................................................i
Organization of This Manual .....................................................................................i
Related Publications..................................................................................................ii
Conventions: Abbreviations......................................................................................ii
Conventions: Diagrams ...........................................................................................vii
Conventions: Fonts and Symbols.......................................................................... viii
Conventions: KB, MB, GB, and TB .........................................................................x
1. Overview of HDLM 1
1.1 What is HDLM? .........................................................................................................2
1.2 HDLM Features..........................................................................................................4
2. HDLM Functions 5
2.1 Devices Managed by HDLM......................................................................................6
2.2 System Configuration.................................................................................................7
2.3 LU Configuration .....................................................................................................10
2.4 Program Configuration .............................................................................................12
2.5 Position of the HDLM Driver and hdisk ..................................................................14
2.6 Distributing a Load Using Load Balancing..............................................................15
2.6.1 Paths to which load balancing is applied ......................................................16
2.6.2 Load Balancing Algorithms ..........................................................................18
2.7 Performing Failovers and Failbacks Using Path Switching .....................................21
2.7.1 Automatic path switching..............................................................................21
2.7.2 Manual path switching ..................................................................................27
2.7.3 Path status transition......................................................................................28
2.8 Monitoring intermittent errors (functionality when automatic failback is used)......32
2.8.1 Checking intermittent errors..........................................................................32
2.8.2 Setting up intermittent error monitoring .......................................................32
2.8.3 Intermittent Error Monitoring Actions..........................................................33
2.8.4 When a User Changes the Intermittent Error Information...........................35
2.9 Detecting errors by using path health checking........................................................38
2.10 Error management ..................................................................................................39
2.10.1 Types of Collected Logs..............................................................................41
2.10.2 Filtering of error information ......................................................................42
2.10.3 Collecting error information using the utility for collecting HDLM error
information (DLMgetras)..............................................................................43