HP XP Continuous Access Software - Manual (Page 30)

30 Continuous Access XP for the XP1024/XP128
If a recordset is lost in transmission from the MCU to the RCU, the MCU’s cylinder bitmap ensures the
missing recordset is marked. After the MCU sends the recordset to the RCU, the MCU does not remove the
sidefile entry for the recordset from its cache until it receives an I/O completion signal (device end) from
the RCU.
Table 9 describes Continuous Access XP Asynchronous suspension conditions and indicates which CU
detects the condition and which pairs are suspended. The Continuous Access XP offloading timer option
(see ” Asynchronous copy option ” on page 70) and timeout group options (see ” Modifying consistency
group options (CT Group Option) ” on page 69) control Continuous Access XP Asynchronous suspension
conditions. For more information about troubleshooting Continuous Access XP Asynchronous suspension
conditions, see the Troubleshooting chapter of the HP StorageWorks Command View XP user guide for XP
Disk Arrays or the HP StorageWorks XP Remote Web Console user guide for XP1024/XP128.
Preparing for Continuous Access XP operations
System requirements
Continuous Access XP operations involve MCUs and RCUs containing primary and secondary volumes,
remote copy connections between MCUs and RCUs, UNIX and/or PC server hosts at primary and remote
sites, and Continuous Access XP. You can use the Command View XP management station or XP Remote
Web Console to manage MCUs and RCUs. Continuous Access XP system requirements are:
• MCU: Disk array with Continuous Access XP installed.
• RCU: Disk array with Continuous Access XP installed.
• UNIX-based and/or PC server platforms: The disk array supports Continuous Access XP operations for
a variety of UNIX and PC-server platforms, including the Sun® Solaris®, IBM® AIX®, HP-UX®, and
Windows NT ® platforms. Contact your HP account support representative for the latest information on
XP1024/XP128 platform support for Continuous Access XP.
• Remote copy connections – Fibre Channel:
• Multimode optical fibre cables at both the MCU and RCU
• For distances from 0.5 km to 11 km, multimode shortwave Fibre Channel interface cables with up
to two switches
Table 9 Continuous Access XP Asynchronous suspension conditions
Suspension condition Detected by Continuous Access XP ASYNC pairs to
be suspended
The MCU could not send a pending recordset to
the RCU before the offloading timer async option
expired.
MCU All Continuous Access XP ASYNC pairs
with P-VOLs in the MCU.
During MCU power-on, the MCU could not
establish communications with the RCU before the
RCU ready timeout group option expired.
MCU All Continuous Access XP ASYNC pairs
with P-VOLs in the MCU.
The RCU could not settle a pending recordset
before the copy pending timeout group option
expired.
RCU All Continuous Access XP ASYNC S-VOLs
in the consistency group.
The RCU could not communicate with the MCU
before the copy pending timeout group option
expired (see ” Modifying consistency group
options (CT Group Option) ” on page 69).
RCU All Continuous Access XP ASYNC S-VOLs
in the consistency group.
The RCU could not receive the recordset
successfully due to a hardware failure.
RCU Only the affected S-VOL.
The RCU detected a logical error while selecting
the recordset to be settled.
RCU All Continuous Access XP ASYNC S-VOLs
in the consistency group or only the affected
S-VOL, depending on type of failure and
error level
Continuous Access XP ASYNC
pair option.
The RCU could not settle the recordset due to a
hardware failure, track condition, or logical error.
RCU