Reference Guide

Support for RPM Redundancy by FTOS Version
FTOS supports increasing levels of RPM redundancy (warm and hot) as described in the table below.
Table 29. Support for RPM Redundancy by FTOS Version
Platform Failover Type Failover Behavior
S4820T Hot Failover Only the failed RPM reboots. All the
line cards and SFMs remain online. All
application tasks are spawned on the
secondary RPM before failover. The
running configuration is synchronized
at runtime so it does not need to be
reapplied during failover.
RPM Synchronization
Data between the two RPMs is synchronized immediately after bootup.
After the two RPMs have done an initial full synchronization (block sync), FTOS only updates changed data (incremental
sync). The data that is synchronized consists of configuration data, operational data, state and status, and statistics
depending on the FTOS version.
Table 30. RPM Synchronized Data by Platform
Platform Failover Type Synchronized Data
S4820T Warm Failover Some NVRAM information, startup-
configuration, line card
configurations, and user-access
configurations.
S4820T Hot Failover Some NVRAM information, startup-
config, line card configurations, user-
access configurations, running-
config, SFM and datapath states, run-
time event log and configuration, and
interface state.
Configuring RPM Redundancy
To select a primary RPM, use the following command. The RPM in slot 0 is the primary RPM by default.
• Manually select the primary RPM.
CONFIGURATION mode
redundancy primary
Example of Viewing RPM Redundancy Configuration
FTOS#show running-config redundancy
!
redundancy auto-failover-limit count 3 period 60
redundancy auto-synchronize full
redundancy primary rpm0
FTOS#
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