System Impact Of Per-Slot Packet Memory Scanning; Network Impact Of Per-Slot Packet Memory Scanning - Extreme Networks BlackDiamond 6804 Troubleshooting Manual

To disable packet memory scanning on a BlackDiamond module and return to the behavior configured
for the global system health check facility, use this command:
unconfigure packet-mem-scan-recovery-mode slot [msm-a | msm-b | <slot number>]
To view the recovery mode configuration for BlackDiamond slots that have per-slot packet memory
scanning enabled, use this command:
show packet-mem-scan-recovery-mode
which displays the following information:
• Global settings for the system health check facility
• Auto-recovery settings for slots that have per-slot packet memory scanning enabled
Here is an example of output from this command:
Global sys-health-check 'online' setting is ONLINE
slot 3: AUTORECOVERY MODE is OFFLINE
MSM-B: AUTORECOVERY MODE is ONLINE
# NOTE Global setting is always online for sys-health-check alarm-level
configurations.
It is only offline when 'sys-health-check auto-recovery <#> offline' is
configured.

System Impact of Per-Slot Packet Memory Scanning

System impact depends on the command option selected (offline vs. online) and the modules in service.
Choosing
offline
protocols both within the system housing the modules and within attached devices. If the disabled
module is an MSM64i and is the master, the system will reboot, causing the slave MSM to assume the
role of master MSM. If the MSM is an MSM3 and is the master, a failure causes a hitless failover to the
slave MSM3. As a consequence, MSM-3 and redundant line modules are great candidates for the offline
option.
Choosing
online
communication issues within the system, as well as affecting or corrupting traffic traversing the switch.
You should take great care to ensure that a module in this state is identified and replaced as soon as
possible.

Network Impact of Per-Slot Packet Memory Scanning

Keep in mind that the
when one of these conditions is true:
• More than eight defected are detected.
• Three consecutive checksum errors were detected by the system health checker, but no new defects
were found by the memory scanning and mapping process.
• After defects were detected and mapped out, the same checksum errors are again detected by the
system health checker.
Encountering one of these conditions might cause different reactions, depending on the type of module
involved. Line modules will trigger applicable recovery mechanisms for all attached devices. MSM-64i
Advanced System Diagnostics and Troubleshooting Guide
causes failed modules to be removed from service. This action triggers recovery
keeps the module in service no matter how many errors are detected, causing
option specifies that a module is to be taken offline and kept offline
offline
Per-Slot Packet Memory Scan on BlackDiamond Switches
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