SSP Failover Situations

An automatic failover is triggered when a failure in the dual SSP configuration affects the proper operation of the main SSP. Failure points can be caused by the following:

• Failed network connections

• SSP system failure due to a

  • System panic

  • Complete power failure

  • Drop in the OpenBoot PROM (OBP) that persists for five minutes or less

• Resource depletion

  Resource depletion refers to the insufficient amount of disk space and virtual memory needed to perform SSP operations. If these resources drop below a certain threshold, the fod daemon initiates a failover. These resources are stored in the ssp_resource(4) file and can be modified using the setfailover command. For details, see "To Modify the Memory or Disk Space Threshold in the ssp_resource File".

However, note that failover will not occur when it has been disabled by operator request or when certain failure conditions prevent the failover. The various failure conditions and the resulting failover actions are summarized in Chapter 10, SSP Internals. Chapter 10, SSP Internals10 identifies and explains the different points of failure detected by the failover process.