HP XP RAID Manager Software - Manual (Page 51)

For more information, see:
•
“Switching off the power supply” (page 51)
•
“Replacing the microcode offline” (page 51)
Switching off the power supply
NOTE: Stop the host I/O to the P-VOL before switching off the power supply for the storage
system.
When you restore the power, SS’s behavior depends on the following:
If data in shared memory existed after switching off the power supply
If information in the shared memory exists after you have switched off the power supply, you can
use the pools and pairs. However, since the storage system checks the status of the pools and the
pool-VOLs, if the pool-VOLs are blocked at the time you switch off the power supply, the pool will
be blocked and the status of the pairs changes to “PSUE”. When this occurs, you must restore the
power and then recover the pools.
When you store snapshot data by consistency group, if you switch off the power supply before
the status of all the pairs in a consistency group has changed completely, the snapshot data will
not resume storing. When you restore the power, the status of some pairs may remain unchanged.
If information in shared memory is lost after switching off the power supply
If information in the shared memory is lost after switching off the power supply, the information
about pools and pairs is also lost. If this occurs, complete the following:
1. Restore the power.
2. Recreate the pools and pairs.
For more information about creating pairs, see “Creating pairs” (page 37) .
For more information about creating pools, see “Creating data pools” (page 23) .
Replacing the microcode offline
You usually replace the microcode online. If you replace it offline, the pool and pair information
in shared memory is lost and you must recreate it. For example, when you need to change the
configuration of shared memory.
Maintaining the storage system 51