Switchover Operation

The following two switchover operations are supported:

Table 2.9 Switchover operations
Item	Content	Remarks
Switchover operations	Active-Standby Operation
Switchover operations	Active-Active Operation	When the configuration is for performing physical/virtual L-Server switchover (VM host/VM guest), the Active-Active operation cannot be performed.

Differences between the operations are as follows:

Active-Standby Operation

An operation that cleans up the configuration of the switchover destination site in order to take over that of the switchover source before a switchover.

Select this operation when all resources in the switchover destination site are used for a switchover, such as in a disaster.

The configuration of the switchover destination site is cleaned up before a switchover.
Collecting the configuration information of the switchover destination site in advance enables the information to be restored after failback is performed.

Active-Standby Operation

Figure 2.5 Active-Standby Operation

Active-Active Operation

An operation that maintains the configuration of the switchover destination site while taking over that of the switchover source during a switchover.

Select this operation when some resources in the switchover destination site are used for a switchover while services are continued.

Physical servers and network devices required for importing the target configuration of the switchover source site must be prepared on the switchover destination site in advance.

When using the physical servers and network devices for other purposes until just before a switchover, those to be stopped for the switchover, and tenants, L-Platforms, and L-Servers which operate using those physical servers and network devices must be defined in advance.

It is necessary to delete the tenants, L-Platforms and L-Servers which were operating when switchover was performed. For details of the corrective actions, refer to "4.2.1 Stopping Services and Releasing Resources [Switchover Destination Site]".

It is possible to restore deleted tenants, L-Platforms and L-Servers after performing failback. For details, refer to "When Restoring the Switchover Destination Site after Failback" in "4.5 Operation after Failback".

Estimate the number of resources to be used on the switchover destination site used for switchover based on the following conditions.
- For the following resources, it is recommended that the same number of resources as on the switchover source site are provided on the switchover destination site.
  - VM hosts and physical servers in the VM pools and server pools used by the switchover target tenant

The reason this is recommended is because when all of the following conditions are met, there is a possibility that recovery of virtual L-Servers or physical L-Servers on the switchover destination site may fail due to a lack of resources.

- When the same number of VM hosts and physical servers as on the switchover source site are not provided at the switchover destination site

- When limitation of switchover scope is not performed

For the following resources, provide the same number of resources on the switchover source site as on the switchover destination site.
- Network devices used by the switchover target tenant

When performing switchover or failback in phases, provide the network devices to be used for each phase of switchover.

For the resources provided on the switchover destination site, take appropriate actions according to the usage status of the resources, as follows:

When not using the resources until switchover is performed

No action required.

When using the resources for another purpose until switchover is performed

Identify the L-Platforms and L-Servers that use these resources using the CLI or the GUI in advance.

Then, stop the identified L-Platforms and L-Servers during the switchover procedure.

The physical servers and network devices used for the switchover cannot be used for the original services of the switchover destination site until failback of the switched configuration is completed.
Perform failover/failback by tenant. Neither failover nor failback are possible by site. For details on the switchover levels, refer to "2.3 Switchover Levels".
There are some notes on the setting of resource names, etc. For details, refer to "2.6.3 Items to Be Different between the Switchover Source and Destination Sites".
Editing of configuration files may be necessary. For details, refer to "2.6.5 Configuration Files for Matching Details between the Switchover Source and Destination Sites".
There are specified settings for L-Platform templates. For details, refer to "Creation of Information on L-Platform Templates for Active-Active Operation" in "3.4 Configuring Managed Resources".
There are some notes on operations after switchover. For details, refer to "When Switchover Was Performed Using the Active-Active Operation" in "4.3 Operation after Switchover".
Different prefixes must be set for the software IDs of the switchover source and destination sites in advance.

When switchover is performed between sites with the same prefix set, the IDs of software information with the same software ID in the sites may be changed during import.

For details on how to set prefixes for software IDs, refer to "Appendix A Settings for Software ID Prefixes".

Figure 2.6 Active-Active Operation

2.2 Switchover Operation

Active-Standby Operation

Active-Active Operation