HP StorageWorks XP24000 Continuous Access Software User and Reference Guide, v01 (T5278-96002, June 2007)

Table 6 Split Types (PSUS)
Type
Applies to
Description
PSUS, P-VOL
by
Operator
P-VOL
(Continuous Ac
cess
Synchronous on
ly)
Theusersplit thepairfrom the MCUusing the P-VOL Failure
option. The S-VOL split type is PSUS-by MCU.
PSUS, S-VOL
by
Operator
P-VOL, S-VOL
Theusersplit thepairfromthe MCUorRCU usingthe S-VOL option.
PSUS, by
MCU
S-VOL
TheRCU receivedarequest from theMCU to splitthe pair. The
P-VOL split t ype is PSUS-P-VOL by Operator or PSUS-S-VOL by
Operator.
PSUS, Delete
pair to RCU
P-VOL
The MCU detec
ted
that the S-VOL status changed to SMPL because
the
user released the pair (pairsplit-S) from the RCU. The pair
cannot be resynchronized because the S-VOL does not have the
PSUS/PSUE status.
Table 7 Consisten cy Sta tus for Split/Suspende d C on tin uous Access Asynchronous
S-VOLs
Consistency Status
(displayed at RCU)
Description
Volume
This Conti
nuous Access Asynchronous pair was probably split or suspended
alone. Upd
ate sequence consistency between this S-VOL and other S-VOLs in this
consiste
ncy group is not ensured. This S-VOL cannot be used for disaster recovery
at
the sec
ondary site. Thisstatusisindicated when:
•
This pair
was split by the user using the Suspend Range-LU pairsplit option.
•
This pai
r
was suspended due to a failure that did not affect the entire
consist
ency group, and the Error L evel pair option forthispairisset to LU.
Group
This Continuous Access Asynchronous pair was split or suspended along with the
other pairs in its consistency group. Update sequence consistency between this
S-VOL and other S-VOL s in this consistency group is ensured. This S-VOL can be
used for disaster recovery at the secondary (remote) system (after releasing the
Continuous Access pair from the RCU). This status is indicated when:
•
This pair was split by the user using the Suspend Range-Group pairsplit option.
• All
pairs in this consistency group were suspended due to a failure that affected
the entire consistency group (not just one pair) (for example, MCU-RCU
communications failure).
•
One pair in the group was suspended due to a failure that did not affect the
entire group, and the Error Level pair option for this pair is set to Group.
Continuous Access Suspend Types
Table 8 on page 31 lists an d describes the Continuous Access suspend t ypes, which indicate
the reason for the suspension. Continuous Access Synchronous pairs can only be suspended
by the MCU. Continuous Access Asynchronous pairs can be suspended by the MCU or by the
RCU. For further information on Continuous Access A synchronous suspension conditions, see
“Continuous Access Asynchr onous Suspension Conditions”onpage31.
The MCU suspends a Continuous Access pair when it detects any of the following suspension conditions:
• When the MCU detects tha t the user has released the pair from the RCU,
• When the MCU detects an error condition related to the RCU, the S-VOL, or a Continuous Access
update
copy operation,
• When the MCU is unable to communicate with the RCU, or
• When the MCU detects a Continuous Access Asynchronous suspension c ondition.
30
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