IBM XIV Storage System Copy Services and Migration

Adding a mirrored volume to a mirrored consistency groupThe mirrored volume and the mirrored consistency group must have the following attributes:► The volume is on the same system as the consistency group.► The volume belongs to the same storage pool as the consistency group.► Both the volume and the consistency group do not have outstanding sync jobs, eitherscheduled or manual.► The volume and consistency group have the same synchronization status.► The volume’s and consistency group’s special snapshot (known as last_replicatedsnapshot) have identical timestamps. This means that the volumes must have the sameschedule and at least one interval has passed since the creation of the mirrors.For more information about asynchronous mirroring special snapshots refer to 6.5.4,“Mirroring special snapshots” on page 172.Also, mirrors for volumes must be activated before volumes can be added to a mirroredconsistency group. This activation results in the initial copy being completed and sync jobsbeing run to create the special last_replicated snapshots (refer to Figure 6-7 on page 155).As seen in Figure 6-11, the Mirror panel now shows the status of the active mirrors as RPO OK.All the async mirrors and the mirrored CG have the same mirroring status. Note that syncmirrors shows the status as synchronized.Figure 6-11 Mirror status activeTo add volumes to the mirrored CG the mirroring parameters must be identical, including thelast_replicated timestamps. The RPO and schedule will be changed to match the values setfor the mirrored consistency group. The volumes must have the same status (RPO OK). It ispossible that during the process the status may change or the last_replicated timestamp maynot be updated yet. If an error occurs verify the status and repeat the operation.Chapter 6. Asynchronous Remote Mirroring 157