IBM 26R0881, Installation And User Manual

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However, in a more complex environment, it may be convenient to have multiple
domains, where the same addresses can exist in different domains. In this case,
you can generate a separate configuration file for each domain.
CAUTION:
We strongly advise against using multiple configurations on a single network,
since this will override the protections against MAC or FC address duplication
as discussed in “Avoiding address duplication.”
Avoiding address duplication
When creating your OFM configuration file, you need to avoid address
duplication.
Duplication of MAC addresses can cause serious issues with your network. Fibre
Channel address duplication can lead to data corruption if more than one blade is
trying to access the same volume at the same time.
To protect from duplicate addresses, the AMM performs as follows:
1. When a new configuration file is applied, the AMM verifies that it does not
contain internal duplicate addresses.
2. Before applying the configuration, the AMM verifies that the blades that are
about to be re-configured are powered off. This ensures that no addresses are
currently in use.
3.
Before writing the new OFM configuration to the blades, the AMM disables the
OFM configuration on all the blades that are about to be re-configured. As a
result, there can be no address duplication even if the operation has not
completed.
For flexibility, the user can override these checks and apply the configuration even
if the AMM generates warnings that duplicate addresses might exist. In addition, if
the user defines the same address, in two different configuration files, for two
chassis that are on the same network, then the AMM can not protect against
address duplication.
To avoid address duplication, it is best to use a single configuration file for a single
network domain and not use the options to override the protection that the AMM
provides.
Duplicate addresses
An error page results when the configuration file contains duplicate addresses.
If the configuration file contains duplicate addresses, an Open Fabric Manager
Configuration Failure window will display in the AMM Web interface. The
window contains a table. Each row of the table indicates an address that is
duplicated and all of the lines in the configuration file on which the error appears.
If you did not intend to have duplicate addresses, you must press Cancel , fix the
configuration file, and then re-apply it.
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IBM BladeCenter Open Fabric Manager Installation and User's Guide