Configuring Multipathing

  1. Install the device-mapper-multipath package. 

    sudo dnf install device-mapper-multipath

  2. Activate the basic configuration settings of the multipathing feature. 

    sudo mpathconf --enable --with_multipathd y

    This command also creates the /etc/multipath.conf file.

  3. (Optional) To know the status of multipathing, type: 

    sudo mpathconf

  4. Edit /etc/multipath.conf as required.

    For details, see Working With the Multipathing Configuration File.

To display the current multipath configuration, run multipath -ll: 

sudo multipath -ll

The command displays output similar to the following, when multipath is configured properly: 

mpath1(360000970000292602744533030303730) dm-0 SUN,(StorEdge 3510|T4
size=20G features=‘0’ hwhandler=‘0’ wp=rw
|-+- policy=‘round-robin 0’ prio=1 status=active
| ‘- 5:0:0:2 sdb 8:16    active ready running
‘-+- policy=‘round-robin 0’ prio=1 status=active
  ‘- 5:0:0:3 sdc 8:32    active ready running

The sample output shows that /dev/mapper/mpath1 subsumes two paths (/dev/sdb and /dev/sdc) to 20 GB of storage in an active/active configuration using round-robin I/O path selection. The WWID that identifies the storage is 360000970000292602744533030303730 and the name of the multipath device under sysfs is dm-0.

For more information, see the mpathconf(8), multipath(8), multipathd(8), multipath.conf(5), and scsi_id(8) manual pages.