Hitachi MK-96RD626-07 - Manual (Page 122)

5-30 Performing Universal Volume Manager Operations
Hitachi Universal Storage Platform V/VM Universal Volume Manager User’s Guide
Turning On or Off the Storage System
This section describes the procedures to turn on or off the power supply of the
local storage system and the external storage system after the Universal
Volume Manager operation has been started.
This section includes the following procedures, and uses ShadowImage as an
example:
• Commands for Turning On or Off Only the External Storage System
• Turning On or Off Only the External Storage System
• Turning On or Off Only the Local Storage System
• Turning On or Off Both Storage Systems
When you turn on or off the power supply of only external storage system, you
need to execute the
Universal Volume Manager commands .
Cautions:
• When you want to turn off both the local storage system and the external
storage system, you first need turn off the local storage system, and then
turn off the external storage system.
• When you want to turn on both the local storage system and the external
storage system, you first need to turn on the external storage system, and
then turn on the local storage system.
Commands for Turning On or Off Only the External Storage System
When you turn on or off the power supply of only external storage system
while the power supply of the local storage system keeps on, you need to
execute the following Universal Volume Manager commands.
The commands used for the procedure are as follows:
• Disconnect Subsystem command
The Disconnect Subsystem command should be executed when the
external storage system is maintained or stopped on purpose. When the
Disconnect Subsystem command is executed, the acceptance of the host
I/O to the external volume that is mapped as the internal volume is
stopped. Then all the data that should belong to the external volume is
written to the external volume from the cache memory of the local storage
system (all the data is destaged).