How to Set Multipath storage connections with Round Robin Policy on single VMWARE host

When installing single VMware ESXI host you do not see all the option regarding multi path settings, all those setting need to be done through CLI

First you need to start SSH on the host : go to host->manage -> services-> start ssh

Next you need to connect to the host with putty or similar.

To list the attached storage devices :

esxcli storage core device list

This will show you all the storage device you have, find that the device is supporting multipath

Multipath Plugin: NMP

To get the list of all active path to the storage

esxcli storage core path list
esxcli storage nmp device list

You should check the setting for the Path Selection Policy (PSP) and the Working Path should be only one network card active when the policy is Fixed mode

Now we need to change the default policy from Fixed mode to Round Robin Where policy is: 

• VMW_PSP_MRU for Most Recently Used mode
• VMW_PSP_FIXED for Fixed mode
• VMW_PSP_RR for Round Robin mode

Run this command to get the disk first number naa.XXXX :

esxcfg-mpath -l

Run this command to change the policy to Round Robin on any LUN you want, in this example on all the LUN that start with naa.XXXX:

for i in `esxcli storage nmp device list | grep '^naa.xxxx'` ; do esxcli storage nmp device set --device $i --psp VMW_PSP_RR; done

another example, this change the policy on all Zadara disks to Round Robin:

for i in `esxcli storage nmp device list | grep "Zadara" | cut -d '(' -f2 | cut -d ')' -f1` ; do esxcli storage nmp device set --device $i --psp VMW_PSP_RR; done

a reboot for the host is recommended after changing policy .

Run 

esxcli storage nmp device list

look for this:

in working path you should see some cards participating in the path and the policy show be VMW_PSP_RR

Run

esxcli storage core device stats get

make sure you do not see any errors in transmissions  .

To Adjust the I/O limits on the policy from 1000 to 1 :

https://kb.vmware.com/s/article/2069356

Good Luck