HP XP Data Shredder Software - Manual (Page 32)

NOTE:
As you turn the local array's power off, all data for the external LU in the local array's cache memory is
written in the external LU (all data is destaged).
To power local arrays on
CAUTION:
When you want to turn on both the local array and the external array, you first need to turn on the external
array, and then turn on the local array.
1. Power on the external array containing the external LU mapped as a local array internal LDEV.
2. Turn on the local array's power.
CAUTION:
When the local array is powered off after executing the Disconnect Subsystem command, you cannot
access the mapped external LU from the local array when you first power on the local array. You must
execute the Check Paths & Restore Vol . command to resume using the mapped external LU. The Check
Paths & Restore Vol. command checks if the defined information and actual status of the external LU
mapped as a local array volume match. If the external LU is ready to be used as a mapped volume, the
LU is set to accept I/Os and you can resume using the volume as a mapped volume.
CAUTION:
When the Disconnect Subsystem or Disconnect Volume command is executed and all data in cache
memory is written to the external LU, the displayed information for Ex-Dev. Status in the Device list
becomes Disconnect.
Powering external arrays on or off
To power external arrays off
1. Stop read and write I/Os to the external LU that is mapped as a local array internal LDEV and is
located in the external array you want to power off.
2. Execute the Disconnect Subsystem command for the external array you want to power off.
Additional I/O to the external LU is stopped and all data in the local array cache memory is written
to the external LU (all data is destaged). For instructions, see Disconnecting external arrays or LUs .
3. Perform other operations required before powering the external array off.
4. Power the external array off.
CAUTION:
After executing the Disconnect Subsystem command, if you need to use the mapped external LU again,
execute the Check Paths & Restore Vol. command.
To power external arrays on
1. Power on the external array containing the external LU that is mapped as a local array internal LDEV.
32 Preparing for External Storage XP operations