Validations That Occur Before a Takeover

When a takeover is initiated by using the geopg takeover command, the data replication subsystem runs several validations on both clusters. These step are conducted on the original primary cluster only if the primary cluster can be reached. If validation on the original primary cluster fails, the takeover still occurs.

First, the replication subsystem checks that the Hitachi TrueCopy device group is in a valid aggregate device group state. Then, the replication subsystem checks that the local device group states on the target primary cluster, cluster-newyork, are not 32 or 52. These values correspond to a SVOL_COPY state, for which the horctakeover command will fail. The Hitachi TrueCopy commands used for the takeover are described in the following table.

Table 11–2 Hitachi TrueCopy Takeover Validations on the New Primary Cluster

Aggregate Device Group State	Valid Local State Device Group State	Hitachi TrueCopy Takeover Command Issued on cluster-newyork
SMPL	All	No command is issued.
Regular primary	All	No command is issued.
Regular secondary	All Regular secondary states except 32 or 52  For a list of Regular secondary states, refer to Table 10–1 and Table 10–2.	horctakeover -S -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	All	No command is issued.
Takeover secondary	All	pairsplit -R-g dgpairsplit -S-g dg