HP XP External Storage Software - Manual (Page 89)

When the Check Paths & Restore Volume command is executed and the external volume is
ready to be restored as the mapped volume, the external volume is set to accept the I/Os and
you can resume using the external volume as a mapped volume. However, if the external
volume is not ready to be restored, the external volume status remains blocked.
Turning On or Off Only the External Storage System
To turn off the power supply of the external 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 and is contained in the external storage system that you want to turn off.
2. Execute the Disconnect Subsystem command for the external storage system that you want to
turn off.
The additional I/O to the external volume is stopped and all the data in the local cache
memory is written in the external volume (all the data is destaged).
For the procedure to execute the Disconnect Subsystem command, see “Disconnecting External
Storage System or Disconnecting External Volume” (page 91) .
3. Perform other operations that are required before turning off the local storage system.
4. Turn off the power supply of the external storage system.
CAUTION:
•
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:
1.
Turn on the external storage system that contains the external volume, which is mapped
as an internal volume.
2. Execute the Check Paths & Restore Volume command of the XP External Storage.
For the procedure to execute the Check Paths & Restore Volume command, see “Checking
Connection Status and Resuming External Volume Operation” (page 93) .
•
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 using 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.
3. Turn off the power supply of the local storage system.
All the data for the external volume in the local cache memory is written in the external volume
(all the data is destaged).
To turn on the power supply of the local storage system to restart from the turned off status:
Turning On or Off the Storage System 89