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1+1 backup: Two components must mirror each other. If the master component is Down,
the slave component takes over the previous component to ensure that the system service
is not interrupted.
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n+1 backup: If you need n similar components to provide services, another component is
necessary to act as the backup for all the n components. If one of the n components fails,
the backup component takes over the faulty component to ensure the smooth service.
At present, the router provides the following hardware backup functions:
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Fabric Board: 3+1 backup
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Main Control Unit (also named main board): 1+1 backup
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Service Process Unit (also named service board): 1+1 or n+1 backup
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Power Module: 1+1 backup
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Cool Fan: n+1 backup
The system performs the AMB/SMB switchover on the premise of 1+1 backup of the main
board, that is, two main boards.
HSB
HSB is a key technology providing hot backup.
The components and terms related to HSB are described as follows:
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Active Main Board (AMB): indicates the current active main board of the two main boards
on a router.
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Standby Main Board (SMB): indicates the backup main board of the two main boards on
a router.
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HA channel: indicates the communication channel between the AMB and SMB.
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Switchover: indicates the AMB is switched to the SMB. It is triggered by the commands
or by a serious fault. In the switchover, the original AMB is reset and becomes an SMB.
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Smooth: After the switchover is performed on a router, the SMB is switched to be the AMB,
but the data in different modules on the new AMB may be inconsistent. Thus, the data
needs to be synchronized on the new AMB.
The HSB can back up the static and dynamic configurations of the system from the AMB to the
SMB.
The AMB and SMB communicate as shown in
.
HUAWEI NetEngine80E/40E Router
Configuration Guide - Reliability
6 GR Configuration
Issue 02 (2014-09-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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