HP StorageWorks Data Replication Manager HSG80 ACS Version 8.7P Configuration Guide (AA-RPHZF-TE, March 2004)

Remote Copy Set Features
37Data Replication Manager HSG80 ACS Version 8.7P Configuration Guide
Note: This switch is valid only in normal error mode with write history logging enabled (not
failsafe).
The RESUME switch initiates the mini-merge restore of the specified remote target unit. This
switch enables the initiator to read the log unit and send the write commands, in order, to the
target, which brings the target into congruency with the initiator. For more information on
mini-merge, see “Write History Logging” on page 39.
Note: The SET AssociationSetName NOLOG_UNIT command terminates any suspended
targets that are currently active and marks them for full copy.
Error Mode Switch
The following command sets the error mode condition:
SET RemoteCopySetName ERROR_MODE=FAILSAFE or
SET RemoteCopySetName ERROR_MODE=NORMAL
The failsafe error mode causes a remote copy set to become failsafe locked if the target
becomes inaccessible or the initiator unit fails. When failsafe is locked, the remote copy set is
inaccessible.
If a dual link failure occurs, the target is not removed but is marked invalid. When the target is
accessible again, a full copy operation is started. When the copy operation is completed, the
failsafe locked condition is cleared.
If the error mode switch is set to NORMAL, write operations are allowed to continue even when
a dual link or disk error is present. NORMAL is the default setting.
Note: You cannot enable the failsafe switch with write history logging enabled.
Association Sets
An association set is a group of remote copy sets that share common attributes. Members of an
association set can be configured to transition to the same state at the same time. For example,
if one association set member assumes the failsafe locked condition, all other members of the
same association set assume the failsafe locked condition as well.
An association set may also be used to simply share a write history log between a group of
remote copy set members that require efficient use of the log space.
Association Set Characteristics
Things to remember about association sets include:
■ Association sets can have up to 12 remote copy sets as members.
■ Association sets can share a write history log, if enabled.
■ Synchronous or asynchronous operation mode and members may be set differently.
■ If ORDER_ALL is set, in order execution of commands across the remote copy sets in the
association set is required.