Select three of the steps for configuring iSCSI Software Initiator multipathing when load balancing with a single vSphere standard switch. (Choose three.)
A.
Change the Path Selection Policy to Round Robin (VMware)
B.
Enable Override switch failover order
C.
Enable Route based on IP Hash
D.
Enable iSCSI port binding on the VMkernel object or objects
E.
Add VMkernel adapters to the iSCSI Network Configuration
D also seems to be good, no?
Based on http://www.vmware.com/files/pdf/techpaper/vmware-multipathing-configuration-software-iSCSI-port-binding.pdf,
To enable vmknic-based software iSCSI multipathing, you must:
• Create two VMkernel port groups and connect one uplink to each of them.
• Bind each VMkernel network adapter to the software iSCSI adapter.
I thought D was correct but it’s a not. The iSCSI binding happens automaticly as part of E (when you add the VMkernel port group to the iSCSI Storage Adaptor).
The question asks to select three steps for “configuring” iSCSI Software Initiator multipathing.
Based on Tony’s link above, the correct answers should be B, D, E. If you browse through the entire document, you’ll see that the configuration of the iSCSI initiator involves the following:
a) Configuring the Network (pg 3)
b) Enabling the iSCSI Software Adapter (pg 7)
c) Activating vmknic-Based Multipathing for Software iSCSI (pg 9)
Changing the path selection policy (Answer A) is done to “verify” the multipath configuration after the VMkernel iSCSI adapters have been configured. (pg 14)
It is not part of the actual configuration process. Besides, it also says on page 14 “NOTE: Verify that the iSCSI array supports the round-robin path policy by contacting the array vendor.” What if it isn’t supported?
“The UI allows one to select different network interfaces for iSCSI use, check them for compliance and configure them with the Software iSCSI Adapter. This multipathing configuration is also referred to as iSCSI Port Binding.”
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There is another important point to note when it comes to the configuration of iSCSI port bindings. On vSwitches which contain multiple vmnic uplinks, each VMkernel (vmk) port used for iSCSI bindings must be associated with a single vmnic uplink. The other uplink(s) on the vSwitch must be placed into an unused state.
http://blogs.vmware.com/vsphere/2011/08/vsphere-50-storage-features-part-12-iscsi-multipathing-enhancements.html
Now, go back into switch properties and go to the properties of each VMkernel port. On the last tab, select “Override switch failover order:” and set only one NIC to be Active, any other move to Unused. You will want each VMkernel port set to use a different NIC.
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Note that if you return to the properties of each VMkernel port you should see the iSCSI Port Binding property checked.
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Once you added the proper iSCSI target and configured said target, you should see two paths listed for the LUN/volumes presented. To turn on Round Robin Multipathing, enter the properties of each datastore and choose “Manage Paths”
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Pick “Round Robin” from the Path Selection drop down and presto! iSCSI Multipathing.
http://sostechblog.com/2011/08/22/vmware-iscsi-multipath-vsphere5/