FCoE’s impact on a Storage Administrator

As FCoE is gaining more traction and moving from a “vision” to a real consideration for many customers, one of the most common question I get from CxOs is: “I understand the benefits of FCoE in my datacenter, but how it will impact my storage team? Will they need to invest significant amounts of timeĀ  new methodologies, commands, concepts, etc when administering the storage network?”

Current FC infrastructure:

fcoe_initial_fc

fcoe_initial_fc

The above is the current FC infrastructure of many customers: hosts, HBAs, FC switches, and storage arrays. In this case, what does a storage admin do to perform activities on the SAN? Let’s look at a use case of turning up a new VMware host:

  • verify the hosts (and storage) have logged onto FC switch A/B (FLOGI process)
  • perform zoning on FC switch A/B
  • perform LUN masking on the storage array
  • rescan HBAs on the host for the LUNs

From a storage administrator perspective they are concerned with HBA WWPNs, storage target WWPNs, zones, zone sets and LUNs.

Sample FCoE integration scenario:

fcoe_midphase_a

fcoe_midphase_a

Depicted above is a very common logical representation of an initial FCoE deployment. Note: Adopting FCoE is NOT a rip and replace maneuver. Needing to purchase new servers, perform a server or network refresh is a very common time scenario when it is prudent to introduce FCoE into the environment to gain the efficiencies. In the above a pair of FCoE capable switches have been introduced and connected into the environment, along with a new server with a Converged Network Adapter (FCoE adapter which combines a NIC and FC HBA). The above example uses Nexus 5000 series switches, because that is what I most commonly deal with. The red connections carry pure FC traffic, the blue connections carry LAN traffic, and the green connections carry FCoE traffic. The most common way to integrate the Nexus 5000 into the existing FC fabric is to utilize NPIV (core) / NPV (edge). Utilizing this method, the core FC switches simply see the Nexus 5000 as a collection of HBAs instead of another FC switch which makes integration very easy.

How is life different for a storage administrator now when provisioning a new server? One the connections are made, there are a couple of additional steps.

On each Nexus 5000 FCoE switches, a “virtual” fiber channel port needs to be created and bound to the ethernet port the server connects to on each switch. On a Nexus 5000, this is very simple:

n5k(config)# interface vfc ZZ
n5k(config-if)# bind interface ethernet XX/ZZ
n5k(config-if)# no shut
n5k(config-if)# exit

Then, you must map a vsan to the vfc port according to the fabric configuration.

After this step, everything else remains exactly the same!

The storage admin will:

  • verify the hosts (and storage) have logged onto FC switch A/B (FLOGI process)
  • perform zoning on FC switch A/B
  • perform LUN masking on the storage array
  • rescan HBAs on the host for the LUNs

All actions can be taken from the original FC switches.

From a host perspective, the CNA appears to the OS as individual NICs and HBAs. So for the storage administrator they are still dealing with HBAs, WWPNs, zones, zonesets, LUNs, and everything they are familiar with in their traditional environment. No learning curve required! Business as usual from a day to day operational perspective.

When a complete FCoE environment is implemented, the same applies. But instead of doing the zoning at the FC switches, they will be done at the Nexus 5000s because there are no more remaining FC switches. The storage admins still deal with HBAs, WWPNs (thanks to the “virtual fiber channel ports” on the Nexus 5000), LUNs, zones and zone sets. From the storage array side, the same applies.



Categories: Cisco, FC, FCoE

3 replies

  1. FCoE provisioning has been capture with DCNM management application at the following link: http://www.cisco.com/go/dcnm – Video Guide

Trackbacks

  1. Technology Short Take #13 - blog.scottlowe.org - The weblog of an IT pro specializing in virtualization, storage, and servers
  2. FCOE Challenges | storagegene

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