See 2.3(2) Instance.

How you operate TrueCopy(or Universal Replicator) paired volumes and ShadowImage paired volumes differs depending on whether the disk on which the original RDAREA is located is joined to the disk on which the replica RDAREA is located.

The following table shows the combinations. Figure 8-1 and Figure 8-2 show paired volume configurations.

Table 8-2 Pair volume configuration combinations when the inner replica facility is being used

Disk join status	TrueCopy or Universal Replicator paired volumes (between the main site and the remote site)		ShadowImage paired volumes
	Original RDAREA	Replica RDAREA
Joined	Paired	Unpaired	Paired
Not joined	Paired	Paired	Unpaired

Figure 8-1 Pair volume configuration when the disks are joined

Figure 8-2 Pair volume configuration when the disks are not joined

When switching sites, depending on whether the disks containing the original RDAREAs are joined to the disks containing the replica RDAREAs, you either pair the individual TrueCopy(or Universal Replicator) or ShadowImage volumes or release their pairing.

• When the disks are joined
  Take control over the TrueCopy or Universal Replicator paired volumes without changing the ShadowImage paired volumes. During this process, set the paired volumes at the remote site to P-VOL.
  
• When the disks are not joined
  Release the ShadowImage paired volumes at the main site (by setting their pair attributes to SMPL) and take control over the TrueCopy or Universal Replicator paired volumes. During this process, set the paired volumes at the remote site to P-VOL and leave the pairing of the ShadowImage paired volumes at the remote site released (start HiRDB in the pairing released state).
  

Figure 8-3 shows the procedure for switching sites to test disaster preparedness when the inner replica facility is being used. Figure 8-4 shows the procedure for switching sites to perform maintenance when the inner replica facility is being used. Figure 8-5 shows the procedure for switching sites in the event of a disaster when the inner replica facility is being used.

Figure 8-3 Procedure for switching sites to test disaster preparedness when the inner replica facility is being used

Figure 8-4 Procedure for switching sites to perform maintenance when the inner replica facility is being used

Figure 8-5 Procedure for switching sites in the event of a disaster when the inner replica facility is being used