Dynamic Link Manager (for Linux®) User Guide

Version: 9.0.x
Audience: anonymous
Part Number: MK-92DLM113-64
Published: 2025-11-06

Overview of HDLM
What is HDLM?
HDLM features
HDLM functions
Devices managed by HDLM
System configuration
System configuration using an FC-SAN
System configuration using an IP-SAN
LU configuration
Program configuration
Position of the HDLM driver and HDLM device
Logical device files for HDLM devices
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
Automatic failbacks
Manual path switching
Path status transition
The online path status
The offline path status
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)
Utility for collecting HDLM installation error information (installgetras)
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
Cluster support
Creating an HDLM environment
HDLM system requirements
Hosts and OSs supported by HDLM
Storage systems supported by HDLM
Storage systems
HBA (if an FC-SAN is used)
NIC (if an IP-SAN is used)
FCoE
When handling intermediate volumes managed by Hitachi RapidXchange
Related products when using Red Hat Enterprise Linux 7
Cluster software supported by HDLM
Volume managers supported by HDLM
File systems supported by HDLM
Boot disk environments supported by HDLM
Related products when using Red Hat Enterprise Linux 8
Cluster software supported by HDLM
Volume managers supported by HDLM
File systems supported by HDLM
Boot disk environments supported by HDLM
Related products when using Red Hat Enterprise Linux 9
Cluster software supported by HDLM
Volume managers supported by HDLM
File systems supported by HDLM
Boot disk environments supported by HDLM
Related products when using SUSE LINUX Enterprise Server 12
Cluster software supported by HDLM
Volume managers supported by HDLM
File systems supported by HDLM
Boot disk environments supported by HDLM (if an FC-SAN is used)
Related products when using SUSE LINUX Enterprise Server 15
Volume managers supported by HDLM
File systems supported by HDLM
Boot disk environments supported by HDLM (if an FC-SAN is used)
Related products when using Oracle Linux 7
Cluster software supported by HDLM
Volume manager supported by HDLM
File systems supported by HDLM
Boot disk environments supported by HDLM
Related products when using Oracle Unbreakable Enterprise Kernel 7
Cluster software supported by HDLM
Volume manager supported by HDLM
File systems supported by HDLM
Boot disk environments supported by HDLM
Related products when using Oracle Linux 8
Volume manager supported by HDLM
File systems supported by HDLM
Boot disk environments supported by HDLM
Related products when using Oracle Unbreakable Enterprise Kernel 8
Cluster software supported by HDLM
Volume manager supported by HDLM
File systems supported by HDLM
Boot disk environments supported by HDLM
Related products when using Oracle Linux 9
Volume manager supported by HDLM
File systems supported by HDLM
Boot disk environments supported by HDLM
Memory and disk capacity requirements
Memory requirements
Disk requirements
Number of LUs and paths that are supported in HDLM
Virtual environments supported by HDLM
Flow for creating an HDLM environment
HDLM installation types
Knowledge required before you install HDLM
Notes on creating an HDLM environment
Notes on hardware settings
Notes on Linux
Notes on installing HDLM
Notes on an upgrade installation or re-installation of HDLM
Installing HDLM
Preparations for a new installation of HDLM
Operations required for devices to be managed by HDLM
Checking the volume group
Setting in the syslog settings file
Setting the mount point (in Red Hat Enterprise Linux 7, 8, or 9)
Checking the partition
Xen settings
Performing a new installation of HDLM
Preparations for an upgrade installation or re-installation of HDLM
Operations required for devices to be managed by HDLM
Deactivating the volume group
Setting up Xen
Performing a re-installation of HDLM
Performing an upgrade installation of HDLM
Unattended installation of HDLM
Installing HDLM for managing boot disks
Notes on installing HDLM in a boot disk environment
Overview of the procedure for installing HDLM in a boot disk environment
Settings for using an HDLM device or a logical volume (LVM2) on an HDLM device as a boot disk
Upgrade installation in an environment where an HDLM device or a logical volume (LVM2) on an HDLM device is used as a boot disk
Settings for a multipath boot disk environment
Upgrade installation of HDLM in a boot disk environment
Countermeasures for unsuccessful startup of the OS from an HDLM device
When an error message appears and the OS stops
When a prompt for a password for starting maintenance appears, and the OS stops
Settings for LVM2
Notes on using LVM2
When using an HDLM device to create a new logical volume
When moving a logical volume created on a SCSI device in a single-path environment to an HDLM device
Confirming that the logical volume is in a multi-path configuration
Settings for Xen
Settings for KVM
Settings for Oracle
Settings when using a channel board (25-Gbps iSCSI optical)
When you start using a channel board (25-Gbps iSCSI optical)
When you stop using the channel board (25-Gbps iSCSI optical)
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
The process-specific-trace information file
Notes on using the Hitachi Network Objectplaza Trace Library
Creating a character-type device file for an HDLM device
When using Red Hat Enterprise Linux 7, 8, or 9, SUSE LINUX Enterprise Server 12 or 15
Creating file systems for HDLM (when volume management software is not used)
Mounting a file system
Creating a file system
Settings for automatic mounting
Setting the HDLM device for the first time
Migrating from an environment where a SCSI device is already set
Canceling the settings for HDLM
Operations on HDLM-managed devices
Canceling the settings for Oracle RAC
Canceling the Xen settings
Canceling the KVM settings
Canceling the settings for LVM2
Removing HDLM
Removing HDLM
Migration to a single-path boot disk environment
Removing the LVM2 settings after uninstalling HDLM
HDLM operation
Notes on using HDLM
Notes common to OSs
Updating kernel packages and applying OS update packages
When using Oracle Unbreakable Enterprise Kernel, Oracle Linux 7, Oracle Linux 8, Oracle Linux 9, or SUSE Linux Enterprise Server
When you are not using the HDLM device as a boot disk
When you are using the HDLM device as a boot disk
When you are using a logical volume (LVM2) on the HDLM device as a boot disk
When using Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, or Red Hat Enterprise Linux 9
When you are not using the HDLM device as a boot disk
When you are using the HDLM device or the logical volume (LVM2) on the HDLM device as a boot disk
Application of OS security packages
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 corresponding information about an HDLM device, SCSI device, and LDEV
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
Reconfiguring the HDLM operating environment
Replacing HBAs
Preparation for replacing HBAs
Procedure for replacing HBAs
Updating the path information after the host is restarted
Replacing a fiber cable
Replacing the Fibre Channel switch
Changing the HDLM device configuration
Notes on changing the HDLM device configuration
Adding a new LU
Adding a path to an existing LU
Deleting an existing LU
Deleting a path to an existing LU
Changing a device managed by HDLM into one not managed by HDLM
Changing a device not managed by HDLM into one managed by HDLM
Restoring the path of an HDLM device started in disconnected status (when a restart is required)
Restoring the path of an HDLM device started in disconnected status (when a restart is not required)
Restoring the path in disconnected status
Expanding the capacity of an LU
Changing an HDLM device name
About creating a new HDLM device
Note on adding a Hitachi Compute Blade I/O drawer
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 corresponding information about an HDLM device, SCSI device, and LDEV
To display the format of the view operation
Parameters
To display program information
To display path information
To display LU information
To display corresponding information about an HDLM device, SCSI device, and LDEV
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
dlmbootstart utility for creating an HDLM boot disk environment
Format
Parameters
dlmcfgmgr utility for managing the HDLM configuration
Format
Parameters
dlmchname HDLM device name replacement utility
Format
Parameters
Editing the device name replacement definition file
How to edit the device name replacement definition file
Items to be defined in the device name replacement definition file
The utility for displaying HDLM performance information (dlmperfinfo)
Format
Parameters
Displayed performance information
Outputting a CSV file
dlmpr utility for clearing HDLM persistent reservation
Format
Parameters
dlmsetopt utility for setting HDLM driver options
Format
Parameters
dlmstart utility for starting HDLM
Format
dlmupdatesysinit utility for updating system scripts
Format
installgetras utility for collecting HDLM installation error information
Format
Parameters
Error information to be collected
installhdlm utility for installing HDLM
Format
Parameters
Editing an installation-information settings file
How to edit an installation-information settings file
Items to be defined in an installation-information settings file
installux.sh utility for HDLM common installer
Format
Parameters
Log file
Utility for removing HDLM (removehdlm)
Format
Parameters
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
KAPL12001 to KAPL13000
KAPL13001 to KAPL14000
KAPL15001 to KAPL16000
Notes on Linux commands and files
Notes on the /proc/partitions file
Notes on Linux commands
Notes on the iostat command
Notes on the mkfs command
Notes on the fdisk, gdisk, and sgdisk commands
Notes on the sar command
Notes on the fdisk , parted, gdisk and sgdisk commands
Notes on the parted command
How to set up the kdump function
Prerequisites
Setup procedure
Add a disk for the kernel dump output
Specify the kernel dump output destination
Create an initial RAM disk image file for the kdump function
Verify that the kernel dump is collected correctly
Notes
Manually setting a boot disk environment
Settings for a multipath boot disk environment
HDLM-supported kernels that handle CPU vulnerabilities by the Retpoline method
List of the HDLM-supported kernels that handle CPU vulnerabilities by the Retpoline method
Functional differences between versions of HDLM
Functional differences between version 9.0.2 and versions earlier than 9.0.2
Functional differences between version 9.0.0 and versions earlier than 9.0.0
Functional differences between version 8.7.8 and versions earlier than 8.7.8
Functional differences between version 8.7.3 and versions earlier than 8.7.3
Functional differences between version 8.7 and versions earlier than 8.7
Functional differences between version 8.6.4 and versions earlier than 8.6.4
Functional differences between version 8.6.2 and versions earlier than 8.6.2
Functional differences between version 8.5.3 and versions earlier than 8.5.3
Functional differences between version 8.0 and versions earlier than 8.0
Functional differences between version 7.6 and versions earlier than 7.6
Functional differences between version 7.2 and versions earlier than 7.2
Functional differences between version 6.2.1 and versions earlier than 6.2.1
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
Functional differences between version 5.9.4 or later and versions earlier than 5.9.4
Functional differences between version 5.9.1 or later and versions earlier than 5.9.1
Functional differences between version 5.9 or later and versions earlier than 5.9
Functional differences between version 5.8 or later and versions earlier than 5.8
Functional differences between version 5.7.1 or later and versions earlier than 5.7.1
Functional differences between version 5.7.0-01 or later and versions earlier than 5.7.0-01
Functional differences between version 5.7 or later and versions earlier than 5.7
Functional differences between version 5.6.3 or later and versions earlier than 5.6.3
Functional differences between version 5.4 or later and versions earlier than 5.4
Acronyms and abbreviations
Acronyms and abbreviations

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