Specifications

50 ExtremeWare XOS 11.0 Concepts Guide
Managing the Switch
Relaying Configuration Information
To facilitate a failover from the master MSM to the backup MSM, the master transfers its active
configuration to the backup. Relaying configuration information is the first level of checkpointing.
During the initial switch boot-up, the master’s configuration takes effect. During the initialization of a
standby or backup MSM, the master’s saved configuration is copied to local flash. After the
configuration is saved, the master transfers the current active configuration to the backup. After the
MSMs are synchronized, any configuration change you make to the master is relayed to the backup and
incorporated into the backup’s configuration copy.
NOTE
To ensure that all of the configuration commands in the backup’s flash are updated, issue the save
command after you make any changes.
If a failover occurs, the backup MSM continues to use the master’s active configuration. If the backup
determines that it does not have the master’s active configuration because a run-time synchronization
did not happen, the backup uses the configuration stored in its flash memory. Because the backup
always uses the master’s active configuration, the active configuration remains in affect regardless of
the number of failovers.
NOTE
If you issue the reboot command before you save your configuration changes, the switch prompts you
to save your changes. To keep your configuration changes, save them before you reboot the switch.
Bulk Checkpointing
Bulk checkpointing requires that the master and backup run-time states be synchronized. Since
ExtremeWare XOS runs a series of applications, an application starts checkpointing only after all of the
applications it depends on have transferred their run-time states to the backup MSM.
After one application completes bulk checkpointing, the next application proceeds with its bulk
checkpointing.
To monitor the checkpointing status, use the show checkpoint-data {<process>} command.
To view the status of bulk checkpointing and see if the backup MSM is synchronized with the master
MSM, use the
show switch {detail} command.
Dynamic Checkpointing
After an application transfers its saved state to the backup MSM, dynamic checkpointing requires that
any new configuration information or state changes that occur on the master be immediately relayed to
the backup. This ensures that the backup has the most up-to-date and accurate information.
Viewing Checkpoint Statistics
Use the following command to view and check the status of one or more processes being copied from
the master to the backup MSM:
show checkpoint-data {<process>}