Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide

5–6 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide
Table 5–2 DRM Planning Considerations
1. If you lose intersite connections, and both the initiator and target
configurations are functional, the system administrator must determine which
site to use. An intersite connection could include hardware or fiber-related
equipment either at the initiator or target locations.
2. If you lose all access to the target controllers for any reason, immediately
remove the remote copy set targets if either of the following two conditions
apply:
❏ None of the remote copy sets is running with write history logging.
❏ You are running with write history logging but there is a possibility the log
disk may overflow.
3. Use the following CLI command to remove remote copy set targets:
SET RemoteCopySetName REMOVE=TargetRemoteCopyName\DiskName
4. If one of the initiator controllers fails, you can lose access to initiator units
under the following conditions:
❏ Access to target units in a remote copy set with no log disk assigned is lost
for any reason (such as loss of both intersite links or loss of both target
controllers) and
❏ The target units are not removed from all of the remote copy sets.
This is because a unit will not failover between controllers in a pair (such as
from a failed top controller to a functional bottom controller) if that unit is the
initiator of a remote copy set that has a target unit assigned..
If this occurs, you will not be able to access or alter the unit or its remote copy
set in any way from the remaining controller. Access will not be reestablished
until the failed controller is either repaired or replaced. Furthermore, you will
not see any apparent error message indicating that you no longer have access
to the unit. To verify that units are inoperative you must check the status of all
units by issuing the following command:
SHOW UNITS FULL
5. An inoperative unit will indicate the following state as part of its status
display:
State:
Unknown - Pending Remote Copy Set Validation