HP XP P9500 Storage - Manual (Page 65)

system changes the P-VOL status to suspended-by RCU but cannot change the status of the
S-VOLs.
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If a primary or secondary system is powered off and the backup batteries are fully discharged
while Continuous Access Synchronous pairs are suspended, differential data is retained to
SSD. In this unlikely case, MCU copies differential data to RCU when the pairs are
resynchronized.
Planned outage of the primary system
A planned outage of the primary system does not affect Continuous Access Synchronous.
Planned outage of the secondary system or data path
You must split the Continuous Access Synchronous pairs in a secondary system prior to a planned
outage of the system or to a data path component (for example, switch, channel extender).
Procedure 19 To perform a planned outage of a Continuous Access Synchronous secondary system
or data path component
1. Identify the Continuous Access Synchronous P-VOLs that are paired with S-VOL in the secondary
system that is to be powered off.
For data path outage, identify all P-VOLs in the primary system that use the path or component
to be powered off.
You need to know the MCU, CU, and ID (port, GID, LUN) for each of the P-VOLs.
2. Connect to each primary system that contains affected P-VOLs and split all affected Continuous
Access Synchronous pairs. Confirm the changed pair status (Pair Operation window or Detailed
Information dialog box).
3. Perform the planned outage of the secondary system or data path.
4. When the secondary system is fully powered on and ready, resynchronize the affected pairs
at each primary system. Confirm the pair status changes.
Planned outage of the primary and secondary system
When you plan an outage of Continuous Access Synchronous primary and secondary systems at
the same time, the primary system must be powered off first, and powered on last.
Procedure 20 To perform a planned outage of Continuous Access Synchronous primary and
secondary systems
1. Perform the planned outage of the primary system. Because a planned outage does not affect
Continuous Access Synchronous pairs, nothing out of the ordinary must be done regarding
the Continuous Access Synchronous system or operations. Do not power on the primary system
at this time.
2. If a secondary system to be powered off is connected to a primary system that is not powered
off, split the Continuous Access Synchronous pairs before powering off the secondary system.
Confirm the pair status changes.
3. Perform the planned outage of the secondary systems as described in the previous section.
4. Power on the secondary systems. Make sure that they are fully operational and ready to
resynchronize operations before powering on the primary system.
5. Power on the primary systems and make sure that they are ready to resynchronize operations.
If you split any pairs in Step 2, you can also resynchronize (pairresync) those pairs now.
Miscellaneous maintenance
This section provides miscellaneous maintenance information.
Miscellaneous maintenance 65