HP StorageWorks XP Remote Web Console Software User Manual
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Table 9 XP Continuous Access suspend types (continued)
Description
Applies to
Type
The MCU could not find valid control information in its nonvolatile
memory during IMPL. This condition occurs only if the MCU is
without power for more than 48 hours (power failure and fully
discharged backup batteries).
P-VOL, S-VOL
PSUE, MCU IMPL
The XP Continuous Access pair was suspended before the initial
copy operation was complete. Data on the S-VOL is not identical
to data on the P-VOL.
P-VOL, S-VOL
PSUE, Initial Copy
Failed
The RCU received a request from the MCU to suspend the S-VOL
due to MCU power-off. The RCU stops expecting recordsets from
that MCU. The P-VOL status does not change due to MCU
power-off.
S-VOL (XP Continuous
Access Async only)
PSUE, MCU P/S OFF
The amount of sidefile exceeds the specified “current pending
update data rate,” and the RCU data is not transferred within
the specified “offloading timer.”
P-VOL, S-VOL
PSUS, Sidefile
overflow (XP
Continuous Access
Async only)
XP Continuous Access Asynchronous suspension conditions
XP Continuous Access Asynchronous operations involve additional suspension conditions related
to recordset operations. The MCU and RCU detect XP Continuous Access Async suspension
conditions and suspend XP Continuous Access Async pairs. When an XP Continuous Access Async
pair is suspended, cylinders containing the following records are marked in the cylinder bitmap
as modified (to be copied during the pairresync operation):
•
Recordsets created by the MCU, but not yet sent to the RCU. After marking these P-VOL
cylinders as modified, the MCU discards these recordsets.
•
Recordsets sent to the RCU, but not acknowledged by the RCU. The MCU marks these P-VOL
cylinders as modified and discards these recordsets, ensuring that recordsets lost during
transmission to the RCU are identified and marked.
•
Recordsets that reached the RCU, but have not yet been settled. After marking these S-VOL
cylinders as modified, the RCU discards these recordsets.
•
P-VOL records updated by host-requested write I/Os after the pair was suspended (same
function as for XP Continuous Access Synchronous pairs).
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.
describes XP Continuous Access Asynchronous suspension conditions and
indicates which CU detects the condition and which pairs are suspended. The XP Continuous
Access offloading timer option (see
“Asynchronous copy option” (page 86)
) and timeout group
options (see
“Modifying consistency group options (CT Group Option)” (page 84)
) control XP
Continuous Access Asynchronous suspension conditions.
XP Continuous Access volume pair status
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