1.Turn on the external storage system that contains the external volume, which is mapped as an internal volume.
2.Turn on the power supply of the local storage system.
CAUTION:
•When the local 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 local 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 whether there is a match between 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.
•When the Disconnect Subsystem or Disconnect Volume command is executed and all the data in the cache memory is written to the external volume, Disconnect appears for Ext. VOL Status in the Volume Operation window.
Turning On or Off Both Storage Systems
This section explains how to turn on or off the power supply of the local and external storage systems, and uses XP Business Copy as an example.
To turn off the power supply of both storage systems:
1.Stop the read or write I/O to the local storage system.
All read and write I/Os with Fibre Channel connections should be stopped.
2.Split all XP Business Copy pairs (pairsplit operation).
For details on the pairsplit operation, see the HP StorageWorks XP24000/XP20000 Business Copy Software User Guide.
3.Turn off the power supply of the local storage system.
CAUTION: Make sure that the power supply of the local storage system is completely off and then go on to the next step.
4.Turn off the power supply of the external storage system.
CAUTION: Make sure that the power supply of the external storage system is completely off.
To turn on the power supply of both storage systems:
90 Performing XP External Storage Operations