5-32 Performing Universal Volume Manager Operations
Hitachi Universal Storage Platform V/VM Universal Volume Manager User’s Guide
Cautions:
• After you have executed the Disconnect Subsystem command, but
you need to use the mapped external volume again, execute the Check
Paths & Restore Volume command.
• To turn on the power supply of the external storage system to restart
from the turned off status:
– Turn on the external storage system that contains the external
volume, which is mapped as an internal volume.
– Execute the Check Paths & Restore Volume command of the
Universal Volume Manager.
• When the external storage system is turned off after the Disconnect
Subsystem command is executed, you cannot access the mapped external
volume from the local storage system as you just turn the external storage
system on. It is necessary to execute the Check Paths & Restore
Volume command to resume using the mapped external volume. The
Check Paths & Restore Volume command checks the defined
information and the actual status of the external volume mapped as an
internal volume. If the external volume is ready to be used as a mapped
volume, the volume is set to accept the I/Os and you can resume usin
g
the
volume as a mapped volume.
Turning On or Off Only the Local Storage System To turn off the power supply of the local storage system (to turn off on
purpose):
1. Stop the read or write I/O to the external volume that is mapped as a local
storage system internal volume.
2. Perform other operations that are required before turning off the local
storage system, if there is some.
3. Turn off the power supply of the local storage system.
Note: As you turn off the power supply of the local storage system, all the
data, which is for the external volume, in the local
cache memory is written
in the external volume (all the data is destaged).