Configuring Linux Multipathing

You can provide multiple paths to your external storage systems by configuring the everRun system to use Linux multipathing. When everRun software is installed, the device-mapper-multipath package is also installed. However, everRun software does not configure multipath. Follow the instructions provided in the CentOs documentation to configure multipath. See https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/DM_Multipath/.

You must perform the two procedures below.

To disable multipath queue_if_no_path

1. Open the /etc/multipath.conf file for editing and add the features "0" line to the defaults section as shown below:

   # Comment: Add 'devices' below to disable queue_if_no_path in
   
   # /etc/multipath.conf to avoid LVM command hang when
   
   # a multipath LUN loses all paths
   devices {
   device {
   vendor "DGC"
   product "VRAID"
   features "0"
   }
   }
   Note: The example shown above is for an EMC storage array. The values for vendor and product vary according to the manufacturer and model of your storage array.

2. Restart multipathd by issuing the following command:

   service multipathd restart

To exclude internal disks from multipath

Open the /etc/multipath.conf file for editing and modify the defaults section as shown below.

Alternatively, if multipath is enabled, you can an issue the following command.

See https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html-single/DM_Multipath/#ignore_localdisk_procedure for details.

Related Topics

External Storage

Managing External Storage