Alcatel-Lucent 6850-48 Manuale Supplementare

Pagina di 312
Managing CMM Directory Content
CMM Files
OmniSwitch AOS Release 6 Switch Management Guide
September 2009
page 5-9
Redundancy
CMM software redundancy is one of the switch’s most important fail over features. For CMM software 
redundancy, at least two fully-operational OmniSwitch Stackable Series switches must be linked together 
as a stack or two fully-operational CMM modules must be installed in the chassis at all times. In addition, 
the CMM software must be synchronized. (Refer to 
 for more information.)
In OmniSwitch Stackable Series switches, one of the switches has the primary role and the another switch 
has the secondary role at any given time. (The primary and secondary roles are determined by the switch 
number indicated on the LED on the front panel; the lowest number switch becomes the primary switch in 
the stack.) The primary switch manages the current switch operations while the secondary switch provides 
backup (also referred to as “fail over”).
Additional switches in a stack are set to “idle” for the purposes of redundancy. For more information on 
managing a stack of switches, see the “Managing Stacks” chapter found in the appropriate Hardware 
Users Guide
When two CMMs are running in an OmniSwitch Chassis-based switch, one CMM has the primary role 
and the other has the secondary role at any given time. The primary CMM manages the current switch 
operations while the secondary CMM provides backup (also referred to as “fail over”).
Redundancy Scenarios
The following scenarios demonstrate how the CMM software is propagated to other switches in a stack for 
the purposes of coherent redundancy. In the examples below, W represents the working directory and C 
represents the certified directory.
Scenario 1: Booting the Stack
The following diagram illustrates what occurs when a stack powers up. The stack displayed is a three 
switch stack.
Powering Up a Stack
W
C
W
C
W
C
1. Stack is pow-
ered up and boots 
from the certified 
directory.
2. The contents of 
the certified direc-
tory of the primary 
CMM
 switch are 
copied to the 
working directory 
of the secondary 
CMM
 switch. 
The working 
directory is then 
copied to the certi-
fied directory.
3. The contents of 
the certified direc-
tory of the pri-
mary 
CMM
 
switch are copied 
to the working 
directory of addi-
tional switches. 
The working direc-
tory is then copied 
to the certified 
directory.
Switch #1
Switch #2
Switch #3