Dynamic Link Manager (for AIX) User Guide

Version: 9.0.x
Audience: anonymous
Part Number: MK-92DLM111-57
Published: 2026-04-28

Overview of HDLM
What is HDLM?
HDLM features
HDLM functions
Devices managed by HDLM
System configuration
LU configuration
Program configuration
Position of the HDLM driver and hdisk
Distributing a load using load balancing
Paths to which load balancing is applied
When all paths are owner paths
When non-owner paths exist
Load balancing algorithms
Performing failovers and failbacks using path switching
Automatic path switching
Automatic failovers
Priority of switching destination paths
Automatic failbacks
Manual path switching
Path status transition
The online path status
The offline path status
Correspondence between path statuses displayed by the OS and by HDLM
Status transitions of a path
Monitoring intermittent errors (functionality when automatic failback is used)
Checking intermittent errors
Setting up intermittent error monitoring
Intermittent error monitoring actions
When an intermittent error occurs
When an intermittent error does not occur
When the conditions for an intermittent error are changed during error monitoring
When failures occur on all paths while monitoring for intermittent errors
When a user changes the intermittent error information
Detecting errors by using path health checking
Error management
Types of collected logs
Filtering of error information
Collecting error information using the utility for collecting HDLM error information (DLMgetras)
Collecting installation error information using the utility for collecting HDLM installation error information (dlmgetrasinst)
Collecting audit log data
Categories and audit events that HDLM can output to the audit log
Requirements for outputting audit log data
Destination and filtering of audit log data
Audit log data formats
Retry count monitoring function
Checking the retry count monitoring function
Setting up the retry count monitoring function
Operation of the retry count monitoring function
When the path is placed offline by the retry count monitoring function
When the path is not placed offline by the retry count monitoring function
When the retry count monitoring function settings are specified during monitoring by the retry count monitoring function
Cluster support
Creating an HDLM environment
HDLM system requirements
Host and OS support for HDLM
Storage systems supported by HDLM
Storage systems
HBA
When handling intermediate volumes managed by Hitachi RapidXchange
Cluster software supported by HDLM
Memory and disk capacity requirements
Memory requirements
Disk capacity requirements
Number of LUs and paths that are supported in HDLM
Flow for creating an HDLM environment
Types of HDLM installation
Notes on creating an HDLM environment
Notes on installing HDLM
Notes on an upgrade installation or re-installation of HDLM
Notes on the virtual I/O server
Notes on the license key and license key file
Notes on trace files
Notes on storage systems
Notes on the cluster
Notes on the automatic failback
Notes on the queue_depth parameter value for an HDLM-managed device
Installing HDLM
Available installation methods
When performing a new installation, upgrade installation, or re-installation of HDLM
When performing a migration of HDLM
Preparations for a new installation of HDLM
Perform operations for HDLM management-target devices
Set up the hardware
Set up cluster software
Performing a new installation of HDLM
When installing HDLM in a local boot disk environment
When installing HDLM in a boot disk environment
Preparations for an upgrade installation or re-installation of HDLM
Stop applications
Perform operations for HDLM management-target device
Performing an upgrade installation or re-installation of HDLM
When installing HDLM in a local boot disk environment (if HDLM has been deleted or defined)
When installing HDLM in a local boot disk environment (if you did not delete usable HDLM devices)
When installing HDLM in a boot disk environment (if HDLM has been deleted or defined)
When installing HDLM in a boot disk environment (if you did not delete usable HDLM devices)
When installing HDLM on alternate disks
Performing an installation in a multibos environment
Using the nimadm command to simultaneously upgrade HDLM and migrate the OS
Installing HDLM to the SPOT of a NIM resource
Migrating from HDLM version 5.8.1 or earlier to version 5.9 or later
Installing HDLM in an environment running PowerHA 7.2 or a later version
Performing an unattended installation of HDLM
When installing HDLM in a local boot disk environment
When installing HDLM in a boot disk environment
Installing the Hitachi Network Objectplaza Trace Library
Checking the path configuration
Setting up HDLM
Checking the current settings
Setting up the HDLM functions
Setting up load balancing
Setting up path health checking
Setting up the automatic failback function
Setting up intermittent error monitoring
Setting the error log collection level
Setting the trace level
Setting the error log file size
Setting the number of error log files
Setting the trace file size
Setting the number of trace files
Setting up audit log data collection
Setting the audit log facility
Checking the updated settings
Setting up integrated traces
Notes on using the Hitachi Network Objectplaza Trace Library
Displaying the Hitachi Network Objectplaza Trace Library setup menu
Changing the size of integrated trace files
Changing the number of integrated trace files
Changing the buffer size per monitoring interval duration
Adjusting the number of messages to be output per monitoring interval
Finishing the Hitachi Network Objectplaza Trace Library settings
Applying the Hitachi Network Objectplaza Trace Library settings
About the reservation policy
Setting up the operating environment for path health checking
Settings for using PowerHA
Registering the HDLM script for PowerHA
Setting the reservation policy
Settings for using GPFS
Settings for using Oracle RAC 11g, Oracle RAC 12c, or Oracle SEHA 19c
Settings for MISSCOUNT and DISKTIMEOUT
Settings for reservation policy
Removing HDLM
Preparations for HDLM removal
Removing HDLM
When removing HDLM in a local boot disk environment
When removing HDLM in the boot disk environment
Removing a NIM resource from SPOT
Removing Hitachi Network Objectplaza Trace Library (HNTRLib2)
Removing Hitachi Network Objectplaza Trace Library (HNTRLib)
Canceling cluster software (PowerHA) settings
Setting before using Live Update
HDLM operation
Notes on using HDLM
Displaying path information
When a path error is detected
Storage system
Notes on shutting down a host
Notes on errors in a host
Notes on enabling both primary and secondary volumes to be viewed from the same server
Notes on an LVM mirror configuration
Notes on when the OS functionality in not available in a boot disk environment
Notes on replicating a system
Notes on OS migration
HDLM operations using commands
Notes on using commands
Viewing path information
Changing the status of paths
Changing the status of paths to Online
Changing the status of paths to Offline(C)
Viewing LU information
Displaying the correspondences between hdisks, OS management path IDs, and LDEVs
Initializing statistical information for paths
Viewing and setting up the operating environment
Viewing the operating environment
Setting up the operating environment
Viewing license information
Updating the license
Viewing HDLM version information
Viewing HDLM component information
Starting and stopping the HDLM manager
Starting the HDLM manager
Stopping the HDLM manager
HDLM resident processes
Changing the configuration of the HDLM operating environment
Changing an HDLM management-target device
Adding an HDLM management-target device
Deleting an HDLM management-target device
Changing an HDLM management-target device
Changing the default values of hdisk attributes
Automatically performing hdisk reconfiguration
Manually performing hdisk reconfiguration
Changing a path
Adding a path (to a volume group other than rootvg)
Adding a path (to a device included in rootvg)
Deleting a path (of a volume group other than rootvg)
Deleting a path (of a device included in rootvg)
Replacing an HBA
Replacing a fiber cable
Replacing a Fibre Channel switch
Troubleshooting
Information collected by the DLMgetras utility for collecting HDLM error information
Checking error information in messages
What to do for a path error
Examining the messages
Obtain path information
Identifying the error path
Narrowing down the hardware that might have caused the error
Identifying the error location and correcting any hardware errors
Placing the path online
What to do for a program error
Examining the messages
Obtaining program information
What to do for the program error
Contacting your HDLM vendor or maintenance company
What to do for other errors
Command reference
Overview of the HDLM command dlnkmgr
clear (returns the path statistics to the initial value)
Format
To set the path statistics to 0
To display the format of the clear operation
Parameters
To set the path statistics to 0
To display the format of the clear operation
help (displays the operation format)
Format
Parameter
offline (places paths offline)
Format
To place paths offline
To display the format of the offline operation
Parameters
To place paths offline
To display the format of the offline operation
online (places paths online)
Format
To place paths online
To display the format of the online operation
Parameters
To place paths online
To display the format of the online operation
set (sets up the operating environment)
Format
To set up the HDLM operating environment
To display the format of the set operation
Parameters
To set up the HDLM operating environment
To display the format of the set operation
view (displays information)
Format
To display program information
To display path information
To display LU information
To display HBA port information
To display CHA port information
Correspondences between hdisks, OS management path IDs, and LDEVs
To display the format of the view operation
Parameters
To display program information
To display path information
To display LU information
To display HBA port information
To display CHA port information
To display the correspondences between hdisks, OS management path IDs, and LDEVs
To display the format of the view operation
add (adds a path dynamically)
Format
To add a path dynamically
To display the format of the add operation
Parameters
To add a path dynamically
To display the format of the add operation
delete (deletes a path dynamically)
Format
To delete a path dynamically
To display the format of the delete operation
Parameters
To delete a path dynamically
To display the format of the delete operation
refresh (applies storage system settings to HDLM)
Format
To apply storage system settings to HDLM
To display the format of the refresh operation
Parameters
To apply storage system settings to HDLM
To display the format of the refresh operation
Utility reference
Overview of the utilities
DLMgetras utility for collecting HDLM error information
Format
Parameters
List of collected error information
dlmchpdattr utility for changing HDLM default settings
Format
Parameters
dlmgetrasinst utility for collecting HDLM installation error information
Format
Parameters
List of collected error information
dlmmigsts utility for assisting HDLM migration
Format
Parameters
dlmodmset utility for setting the HDLM execution environment ODM
Format
Parameters
The utility for displaying HDLM performance information (dlmperfinfo)
Format
Parameters
Displayed performance information
Outputting a CSV file
dlmpostrestore utility for HDLM restoration support
Format
Parameters
dlmpr utility for clearing HDLM persistent reservation
Format
Parameters
dlmpremkcd utility for preparing for a system backup
Format
Parameters
dlmpreremove utility for executed before removing HDLM
Format
Parameters
dlmrmdev utility for deleting HDLM drivers
Format
Parameters
dlmrmprshkey utility for clearing HDLM persistent reservation (shared-host methodology)
Format
Parameters
installhdlm utility for installing HDLM
Format
Parameters
Items to be defined in an installation-information settings file
Log file
installux.sh utility for HDLM common installer
Format
Parameters
Log file
Messages
Before viewing the list of messages
Format and meaning of message IDs
Terms used in messages and message explanations
Components that output messages to syslog
KAPL01001 to KAPL02000
KAPL03001 to KAPL04000
KAPL04001 to KAPL05000
KAPL05001 to KAPL06000
KAPL06001 to KAPL07000
KAPL07001 to KAPL08000
KAPL08001 to KAPL09000
KAPL09001 to KAPL10000
KAPL10001 to KAPL11000
KAPL11001 to KAPL12000
KAPL13001 to KAPL14000
KAPL15001 to KAPL16000
Functional differences between versions of HDLM
Functional differences between version 8.6.2-01 or later and versions earlier than 8.6.2-01
Functional differences between version 6.2 and versions earlier than 6.2
Functional differences between version 6.1 and versions earlier than 6.1
Functional differences between version 6.0 or later and versions earlier than 6.0
Differences between HDLM version 5.9 or later and version 5.8.1 or earlier
Add-in HDLM driver module
Simplifying the HDLM environment configuration and operation procedures by changes to the logical device files
Changing the HDLM environment configuration and operation procedures by changes to the logical device files
Migrating reservation control settings
Support for a boot disk environment
About settings when upgrading the OS
Eliminating settings when upgrading the OS
Eliminating settings when changing the kernel mode
Changing a virtual I/O server's method of recognizing virtual SCSI disks
Acronyms and abbreviations
Acronyms and abbreviations

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