HP XP Continuous Access Software - Manual (Page 24)

24 Continuous Access XP for the XP1024/XP128
Group options
Continuous Access XP provides the following options for each consistency group: copy pending timeout
and RCU ready timeout. These options are selected when you add a group, and can be modified only
when the group does not contain any P-VOLs in the MCU.
Copy pending timeout
This group option specifies maximum delay allowed for Continuous Access XP Async copy operations.
The RCU suspends all S-VOLs in the group when:
• The RCU has not had any communications from the MCU within the specified time. This situation might
indicate a disaster or failure at the primary site.
• The RCU has received recordsets from the MCUs but has not been able to settle a particular recordset
within the specified time. This situation might indicate the RCU does not have enough resources to
handle remote copy and I/O workloads.
RCU ready timeout
This group option specifies maximum delay allowed for re-establishing MCU-RCU communications
following MCU power-off. During MCU power-on, the MCU re-establishes communications with all
registered RCUs. If the MCU cannot re-establish communications with an RCU within the specified time,
the MCU suspends all affected Continuous Access XP Asynchronous volume pairs.
Group operations
Continuous Access XP Asynchronous provides the following group-based operations to simplify and
expedite disaster and failure recovery procedures:
• Group operations at the MCU:
• Split (pairsplit-r) all pairs in a consistency group. See ”
Splitting Continuous Access XP pairs
(Pairsplit-r) ” on page 85 for a description of the Suspend Range-Group pairsplit-r option.
• Resume (pairresync) all split or suspended pairs in a group. See ” Resuming Continuous Access XP
volume pairs (Pairresync) ” on page 88 for a description of the Continuous Access XP Resume
Range-Group pairresync option.
• Delete (pairsplit-S) all pairs in a group. See ” Deleting Continuous Access XP volume pairs
(Pairsplit-S) ” on page 90 for a description of the Delete Range-Group pairsplit-S option.
• Group operations at the RCU:
• Split (pairsplit-r) all pairs in a consistency group. See ”
Splitting Continuous Access XP pairs
(Pairsplit-r) ” on page 85 for a description of the Suspend Range-Group pairsplit-r option.
• Delete (pairsplit-S) all split or suspended pairs in a consistency group except inconsistent pairs. See
” Deleting Continuous Access XP volume pairs (Pairsplit-S) ” on page 90 for a description of the
Delete Range-C/T pairsplit-S option.
• Delete (pairsplit-S) all pairs in a group regardless of their consistency status. See ” Deleting
Continuous Access XP volume pairs (Pairsplit-S) ” on page 90 for a description of the Delete
Range-Group pairsplit-S option.
Continuous Access XP also provides the Error Level pair option (see ” Continuous Access XP initial copy
and pair options of the Paircreate pane ” on page 84), which triggers automatic suspension of an entire
consistency group. When a Continuous Access XP Async pair is suspended due to failure (not
user-requested), this Continuous Access XP pair option determines whether all pairs in the same
consistency group are also suspended. If you selected the Group error level for the Continuous Access XP
Async pair, all pairs in the same group are suspended. If you selected the LU error level, only the affected
Continuous Access XP Async pair is suspended.
The Error Level pair option is very important for managing Continuous Access XP Asynchronous groups
and planning disaster recovery. The Group error level should be selected for all Continuous Access XP
Async volumes essential to disaster recovery. Suspended Continuous Access XP Async S-VOLs with the LU
error level should not be used for disaster recovery because they are not consistent with the rest of the
volume group.