After a switchover was performed (either manually or automatically), perform either one of the following post-switchover recovery procedures.
Refer to "Chapter 9 Hardware Maintenance" for details on how to replace hardware.
Server failback procedure
Replace failed server hardware
Perform a "Failback" operation to return to a pre-switchover configuration.
Server takeover procedure
Perform the following two operations.
Replace failed server hardware
Perform a "Takeover" operation to keep the configuration created by a server switchover.
Information
For a server takeover procedure, server hardware can be replaced either before or after the "Takeover" operation.
Failback
Use the following procedure to return to a pre-switchover configuration.
Refer to "Conditions for Server Failback" in "9.3 Server Switchover Conditions" of the "ServerView Resource Coordinator VE Setup Guide" for details on the conditions for a server failback.
In the RC console's resource tree, right-click the physical OS or VM host that was switched over to the spare server, and from the popup menu select [Spare Server]-[Failback].
The [Server recovery Failback] dialog is displayed.
Click the <OK> button.
The spare server is stopped and the server OS is switched back to the primary server. The primary server finally starts up and resumes its applications.
Note
When using the backup and restore switchover method, do not start up the original spare server during or after the failback operation.
The primary server and spare server both run the same system image. Having the two servers running together will cause conflicts of IP addresses and other information. This can adversely affect the applications switched back to the spare server.
If it becomes necessary to start the spare server, for maintenance or other tasks, ensure that it does not start up from the same system image as that of the primary server. This can be done by turning off the primary server first, or by stopping the spare server at its BIOS screen (before startup of the OS).
When using the backup and restore switchover method, and newly generated data on the spare server needs to be transferred to the primary server, back up the spare server before performing the failback.
Refer to "Backing up a System Image" in "8.2 Backing Up System Images" and apply the backup instructions to the spare server.
Unless there is a need to keep the data that was generated on the spare server while active, backup of the spare server can be skipped. In that case, a system image backed up prior to failure will be restored to the primary server.
When using PRIMERGY BX servers, the maintenance LED of a primary server is automatically deactivated after a server failback.
Takeover
Use the following procedure to keep the configuration created by a server switchover:
In the RC console's resource tree, right-click the physical OS or VM host that was switched over to the spare server, and from the popup menu select [Spare Server]-[Takeover].
The [Takeover] dialog is displayed.
Click the <OK> button.
The spare server continues operating as the primary server and the server that functioned as the primary server before switchover becomes a spare server.
If the spare server was originally shared by multiple primary servers, all those servers will now use the original primary server as their spare server.
Example
Status before switchover
Application 1: Server A (active) - Server B (spare)
Application 2: Server C (active) - Server B (spare)
Status after a fault in Server A triggered a switchover of Application 1
Application 1: Server A (fault) - Server B (active)
Application 2: Server C (active) - Server B (*1)
Status after replacing server A and letting Server B take over Application 1
Application 1: Server B (active) - Server A (spare)
Application 2: Server C (active) - Server A (spare)
*1: At this point, manual switchover or automatic recovery from server C to server B becomes impossible.
Note
Once server switchover has taken place, Auto-Recovery and manual server switchover cannot be performed until either failback or takeover has been executed.
Perform either failback or takeover to enable switchover to be performed again.
