Adding iSCSI storage to UCS and VMware

Adding iSCSI storage to UCS and vSPhere

NOTE: Ensure all of your service profiles are using the “User Ack” Maintenance Policy before proceeding, or contact your IT service provider for assistance. You can cause outages to your entire infrastructure if you make changes without knowing the consequences.

Create new NIC’s and VLAN’s in UCS

First step is to create a new VLAN to be used for iSCSI.

On the LAN tab click create VLANs

Enter a VLAN Number and name, some specific use cases may use the other options but most will use Common/Global

Once the VLAN is created in UCS we need to create a new VNIC template.

Navigate to the LAN tab and select VNIC templates and click on add

We then create a new vNIC template, I usually use updating templates as these facilitate changes more rapidly however a misconfiguration can cause problems across the entire environment.

We need to create a vNIC template for FI-A and FI-B to allow multiple paths to our NAS to ensure resilience and higher throughput.

We then create a second vNIC template for Fabric B, and select the MAC Pool for Fabric B.

We then need to add our vNIC template to our Updating Service profile template which will then update all of our service profiles (or if you do not use updating SP templates you can do this to each and ever SP).

We now click on the tick box “Use LAN Connectivity Template” which will use our pre configured VNIC template and save us time.

Add a Name, select the vNIC template and use the VMware Adapter Performance Policy as shown below.

You will then be prompted to reboot your blades to add the new vnics to each.

Create a new vSwitch to be used for our iSCSI connections

Add a new VMkernel port

Add both of our NIC’s we created in UCS

Create a name for the first iSCSI VMkernel port

Add the IP address and subnet mask of the first iSCSI VMK adaptor

Click Finish

Now we need to configure a second iSCSI VMKernel adaptor, so on the vSwitch click Properties

Click Add

Select VMkernel, also note the iSCSI option here:

Give this a logical name “iSCSI-2”

Give this a different and subnet mask.

Click finish, and now to set the recommended settings on the vSwtich:

Set the port number to 8, this keeps the overhead required for the vSwitch to a minimum.

The MTU can also be changed here once it is configured on the iSCSI target device and on the network switch. MTU needs to be configured end to end or performance will be degraded not improved.

Set all security to Reject

We now need to set the active and unused adaptors for each iSCSI VMkernel port, select either iSCSI adaptor and click edit

On the NIC Teaming tab, select “Override switch failover order” for our iSCSI adaptor make sure vmnic8 is active and vmnic9 is unused, and for iSCSI-2 vmnic9 should be active and vmnic8 should be unused.

Here is the setting for iSCSI-2

Here is the setting for iSCSI

Once the vSwitch is configured correctly we can add the Software iSCSI adaptor, on the Storage Adaptors section in the Configuration tab click Add

Click OK to add the software iSCSI adaptor

Cilck ok again

The new adaptor will now be shown, select it and click properties (or right click then properties)

We now need to bind our two iSCSI VMkernel ports to the Software iSCSI adapter. Click the Network Configuration tab and click add.

Select one of our adaptors we created earlier and click OK.

Repeat this for the second adaptor so we have both bound as shown below:

The we need to add our iSCSI target, this is done from either the Dynamic Discovery tab or if you have a very old or specific use case the Static Discovery tab.

We are using dynamic discovery which will find any LUN created on our target device, this device has 2 IP addresses and NIC’s so we add both as shown below:

Once we click close we are prompted to do a rescan, we click yes then wait while this finishes.

And we now have our visible devices shown:

We change to the storage tab, then click Add Storage:

We then select the Disk/LUN option (note the SCSI disk section highlighted

We then select our device and click next:

VMFS5 should be selected unless backwards compatibility is needed with ESXI 4.1 or older hsots

Click next twice and then set a datastore name, we have used the following convention (Vendor)_(Protocol)_(Use)_(Storage DRS Pool Name)_VMFS(Incremental Number).


Click next, and set the size. Or choose the maximize space option.


All done, start using your new iSCSI datastore.



Adding iSCSI storage to UCS and VMware


  • tomasa says:

    Great article!!! Thx mate.
    Are you running only the standard vswitch or standard vswitch+vDS?
    In our case, we use vce vblocks + nexus 1000v, any experience with creating the vmkernel ports on the n1kv? Just wondering what the best practice will be if we want to add iscsi storage to the vblocks.

    • says:

      Hey Tomasa,

      If you want to add iSCSI to a Vblock I would recommend getting VCE to do the work. At least get an exception to modify the Vblock or you will not get support for it.

      This article was written with standard, or DVS. But it can be done with the N1kv and a few things to consider that would not be needed for the VMware switches would be to use System VLAN’s, if the N1kv is to be stored on an iSCSI datastore, and to set the MTU on the ethernet port profiles.

      Commands would be (this is from memory as I am at the airport, so excuse mistakes):
      Port-profile type ehternet uplink
      vmware portgroup
      switchport mode drunk
      switchport allowed vlan *,*,*, (for each iSCSI VLAN)
      system VLAN *,* (if needed)
      No shut
      MTU 9000

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