My Oracle Support Banner

Multipath troubleshooting (Doc ID 2253863.1)

Last updated on APRIL 23, 2020

Applies to:

Linux OS - Version Oracle Linux 5.1 and later
Oracle Cloud Infrastructure - Version N/A and later
Linux x86-64
Linux x86

Purpose

Object of this document is to provide details on device mapper multipathing (DM-MP).

Troubleshooting Steps

To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!


In this Document
Purpose
Troubleshooting Steps
 Overview
 Device Mapper Multipathing
 DM-MP consists of 4 components
 DM Path States
 This refers to the DM module(kernel)'s view of the path's state. It can be in one of the two states:
 Path Group State: Path Groups can be in one of the following three states
 This policy selection can be set by the user through /etc/multipath.conf.
 Configuration File (/etc/multipath.conf)
 Rebuilding the initrd (Oracle Linux 5) 
 Rebuilding the initramfs (Oracle Linux 6)
 The Linux SCSI layer sets a timer on each command.
 Misc tips on Linux Native Multipath  
 Removed LUN's Continue to Display as PATH Down in the OS Log
 Process are stuck in D-state. How can I kill them ?
 multipathd –k: Puts your session into interactive mode. Commands can be used to list the current configuration or to change the configuration. For example, <show config> lists the current configuration, and <reconfigure> gets the latest configuration from the configuration file (etc/multipath.conf).
References

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.