Best Practice UCS with iSCSI Storage and Nexus (without iSCSI Boot from SAN) with Disjoint Layer 2?

Stefan Gruber · ‎02-01-2017

Hello how shoult I release an UCS iSCSI Storage Projekt over Nexus

-Is the only answer Disjoint Layer 2?

Pleass Help

Walter Dey · ‎02-02-2017

Hi Stefan

What is the use case for disjoint vlans and iSCSI storage ? separate traffic from FI Northbound ? this would require separate physical links ?

As every server need access to iSCSI, you have to create separate vnics for this iSCSI vlans.

I would not take the extra effort to implement disjoint vlans for iSCSI.

Walter.

Stefan Gruber · ‎02-02-2017

Hi Walter

We want a clean solution with iSCSI

The best way i think are seperate ETH Ports on the Fabric interconnect who are going to the Nexus?.

Because the other sollution is:

If i have 4ETH Uplinks on each FI (2right 2left)
over this 4uplinks ETH and iSCSI traffic is going up over the same Connection,
And than i Cant Cable one right one left to the Nexus.
Than i have to Cable 4 left FI-a and 4 right FI-b like FC Cabeling

Walter Dey · ‎02-02-2017

Hi Stefan

- even with disjoint vlans, links between vnics - IOM, and IOM - FI share iSCSI and Ethernet traffic

- you have 40g per FI which is a lot ! (I assume you implement vpc on the Nexus)

- iSCSI and/or FC: if you experience a bottleneck, its most likely IOPS not bandwidth.

- instead of disjoint vlans, you could also use static pinning ! see eg.

http://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/sw/gui/config/guide/2-2/b_UCSM_GUI_Configuration_Guide_2_2/configuring_lan_pin_groups.html

Stefan Gruber · ‎02-06-2017

I Think about Lan Pin Groups yes.

For Example:

-FI-A Port 17/18/19/20 (one ETH Port Channel) Port17/18 are conect with NexusA and 19/10 are connectet with NexusB

-Same FI-B

-Can i create a "FI-A Lan Pin Group" with FI-A Ports 17/18 who works in an Port Channel

This Pin Group are only connectet with Nexus-A

-Same FI-B

And than i Pin the iSCSI vNics to this two Pin Groups and i don't have traffic to the wrong side?!

Stefan Gruber · ‎02-06-2017

Is that above possible?