Fc-Redirect; Server-Based Discovery For Provisioning Tapes; Target-Based Load Balancing; Sme Scalability - Cisco AJ732A - MDS 9134 Fabric Switch Configuration Manual

About Cisco Storage Media Encryption
S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m

FC-Redirect

Cisco SME performance can easily be scaled up by adding more Cisco MDS 9000 family switches or
modules. The innovative Fibre Channel redirect capabilities in Cisco MDS 9000 NX-OS enable traffic
from any switch port to be encrypted without SAN reconfiguration or rewiring.

Server-Based Discovery for Provisioning Tapes

Cisco SME provides discovery of backend targets using the identity of the host during a session
establishment.

Target-Based Load Balancing

The Cisco SME cluster consists of a set of switches (in a dual-fabric environment) running the Cisco
SME application. Clustering offers target-based load balancing of Cisco SME application services. The
cluster infrastructure allows the Cisco SME application to communicate and coordinate to maintain
consistency and high availability.
Load balancing is achieved by distributing ownership of the various metadata objects throughout the
cluster. Cisco SME assigns hosts to the available Cisco SME interfaces using the following algorithm:
•
•
•
In target-based load balancing, the load on an interface refers to the number of targets assigned to that
interface.
The load balancing command is disruptive to traffic. Ensure that you execute this command at a
Caution
scheduled downtime, otherwise, the existing traffic will be affected.

SME Scalability

The following features improve the scalability and performance of the Cisco SME application by
minimizing the network overhead and maximizing the overall throughput:
•
•
Cisco MDS 9000 Family Storage Media Encryption Configuration Guide
1-6
All hosts for a given target port are always assigned to the same Cisco SME interface.
If a target port is connected to one of the Cisco SME switches, an interface is selected based on the
load from the target-connected switch. That is, the target locality is considered when choosing a
Cisco SME interface for a target.
If a target is connected to a switch that has no Cisco SME interface, then the target is assigned to
the least loaded available interface in the Cisco SME cluster.
The SME application supports the batching of messages where messages of the same type are
combined and sent as a single message. This feature saves a significant amount of overhead and
minimizes the number of messages between the SME process and the cluster process. The reduction
in the traffic load substantially reduces the CPU usage of these processes.
The FC redirect process is optimized by caching the FC redirect messages. This feature reduces the
number of identical messages that are generated each time a new ITL is configured, which reduces
the total number of backend messages.
Chapter 1 Product Overview
OL-18091-01, Cisco MDS NX-OS Release 4.x