How to Configure Multipathing in Linux (RHEL7/CentOS7)

How to configure multipathing on linux, multipath configuration in linux step by step, linux multipathing configuration, multipathing configuration in linux

How to Configure Multipathing in Linux (RHEL7/CentOS7)

This article describes you the step by step procedure to configure the Multipathing in Linux (RHEL7/CentOS7) using Device Mapper Multipathing (DM-Multipath) and helps you to understand the multipath configuration..

Device Mapper Multipathing (DM-Multipath) is a native multipathing in Linux, Device Mapper Multipathing (DM-Multipath) can be used for Redundancy and to Improve the Performance. It aggregates or combines the multiple I/O paths between Servers and Storage, so it creates a single device at the OS Level.

For example, Lets say a server with two HBA card attached to a storage controller with single ports on each HBA cards. One lun assigned to the single server via two wwn number of both cards. So OS detects two devices: /dev/sdb and /dev/sdc. Once we installed the Device Mapper Multipathing. DM-Multipath creates a single device with a unique WWID that reroutes I/O to those four underlying devices according to the multipath configuration. So when there is a failure with any of this I/O paths, Data can be accessible using the available I/O Path.

1. Install the  Device Mapper Multipath package.
Verify the device-mapper-multipath package has been installed or not.
[root@linux1 ~]# rpm -q device-mapper-multipath
If it is not installed, Install the Device Mapper Multipath package using yum to avoid dependencies issue. if yum is not configured, please refer the link Yum Configuration on Linux
[root@linux1 ~]# yum -y install device-mapper-multipath
2. Basic Configuration of Linux Device Mapper Multipathing
Configuration file is /etc/multipath.conf file, take a backup of it. Edit the configuration file to ensure you have the following entries uncommented out.
defaults {
user_friendly_names yes
blacklist {
devnode “sda”
The blacklist includes the devices which are not to be configured in Multipathing. For example, Lets say our OS installed disk is /dev/sda. So the first entry in the blacklist will exclude them. Same for IDE drives (hd).

3. Start and Enable the multipath daemons.
Start the multipath service if not started bydefault.
[root@linux1 ~]# systemctl start multipathd
Enable the multipath service to start on boot.
[root@linux1 ~]# systemctl enable multipathd
4. Check the multipathing status.
The multipath -ll command prints out multipathed paths that show which devices are multipathed. If the command does not print anything out, ensure that all SAN connections are set up properly and the system is multipathed.
[root@linux1 ~]# multipath -ll
mpathb (360014051f89d2bb3300470fa7d4baa10) dm-2 LIO-ORG ,lun0
size=2.0G features='0' hwhandler='0' wp=rw
|-+- policy='service-time 0' prio=0 status=active
| `- 1:0:0:0 sdb 8:16 active active running
`-+- policy='service-time 0' prio=0 status=enabled
  `- 2:0:0:0 sdc 8:32 active active running
The above output shows 1 LUN (mpathb) with 2 paths (sdb and sdc). Linux Multipathing basic configuration is done. Refer this link to check further for  troubleshooting any issue related with multipathing and also understand its terminologies.

Thanks for reading our post. share with your friends. We appreciate your feedback, Leave your comments if any.

Support Us: Share with your friends and groups.

Stay connected with us on social networking sites, Thank you.
YouTube | Facebook | Twitter | Pinterest | Rss
Keywords : Steps to configure multipath in linux, How to configure multipath on linux, multipath configuration in linux step by step, linux multipath configuration redhat, how to configure multipath in rhel step by step, what is multipathing in linux, linux multipath command, linux multipathing, multipath in linux with device mapper, linux multipath tutorial, multipathing in linux tutorials, multipathing in linux pdf, linux multipath command examples, DM Multipath Configuration, setting up DM Multipath configuration, How to Setup DM-Multipath on RHEL & CentOS, iscsi multipath configuration linux, Enabling Multipathing in Linux, device mapper multipath, device mapper multipath linux, multipath in linux with device mapper, linux device mapper multipath howto, device mapper configuration file, how to enable multipathing in linux, working with linux multipathing, managing linux multipathing, how to manage multipath in linux, how to troubleshoot multipathing in linux, how to check multipathing in linux
June 23, 2016

Post a Comment


Contact Form


Email *

Message *

Powered by Blogger.
Javascript DisablePlease Enable Javascript To See All Widget