Validations That Occur Before a Switchover

When a switchover is initiated by using the geopg switchover command, the data replication subsystem runs several validations on both clusters. The switchover is performed only if the validation step succeeds on both cluster.

First, the replication subsystem checks that the Hitachi TrueCopy device group is in a valid aggregate device group state. Then, it checks that the local device group states on the target primary cluster, cluster-newyork, are 23, 33, 43, or 53. The local device group state is returned by the pairvolchk -g device-group-name -ss command. These values correspond to a PVOL_PAIR or SVOL_PAIR state. The Hitachi TrueCopy command given on the new primary cluster, cluster-newyork, are described in the following table.

Table 11–1 Hitachi TrueCopy Switchover Validations on the New Primary Cluster

Aggregate Device Group State	Valid Device Group State on Local Cluster	Hitachi TrueCopy Switchover Command Issued on cluster-newyork
SMPL	None	None
Regular primary	23, 43	No command is issued, because the Hitachi TrueCopy device group is already in the PVOL_PAIR state.
Regular secondary	33, 53	horctakeover -g dg [-t] The-t option is given when the fence_level of the Hitachi TrueCopy device group is async. The value is calculated as 80% of the protection group's Timeout property. For example, if the protection group has a Timeout of 200 seconds, the value of -t used in this command will be 80% off 200 seconds, or 160 seconds.
Takeover primary	None	None
Takeover secondary	None	None