VMware | Automatic fix LUN multipath policy to Round-Robin

A newly (manual) added FC datastore has a default multipath policy of “Most Recently Used (MRU)” or “Fixed” – both means, that there will be only one path used at a time.

We wanted all our datastores to use multiple paths, so we switched all our datastores to “Round Robin (RR)”. With about 10 storage systems and a total of over 200 LUNs spreaded over 10th of clusters, this configuration is a mess.

I’ve written a script for Perl SDK, which connects to the vCenter and loops over all hypervisors and LUNs and sets the policy to “Round Robin”:

unless($policy eq "VMW_PSP_RR"){

   my $new_policy = HostMultipathInfoLogicalUnitPolicy->new(policy => "VMW_PSP_RR");

   $storage_view->SetMultipathLunPolicy(lunId => $id, policy => $new_policy);

   print "fixed $hostname policy on $lun_id\n";

}

Find the complete script on my GitHub Repository.

Side note: using NetApp SAN Storages, you don’t need to switch the policy, because the default policy is already “Round Robin”.