Turning The Local Disk Array's Power On Or Off; To Turn Off The Local Disk Array's Power; To Turn On The Local Disk Array's Power - HP StorageWorks User Manual

This command verifies that the saved information about the mapped external LU matches the actual
external LU status. If the external LU can be used as the mapped local disk array XP LDEV, the external
LU is set to accept I/O operations, and you can continue using the external LU as a mapped LU.
Use this command to restore host I/O operations to a mapped external LU after disabling those
operations using either the Disconnect Subsystem or Disconnect Volume command. You can use the
Check Paths & Restore Vol. command to reestablish I/O traffic to an entire disk array or an individual
LU.
If an error occurs in the external storage path such that the command fails, correct the error so the path
can be restored, and execute the Check Paths & Restore Vol. command again.
For instructions on executing the Check Paths & Restore Vol. command, see
status and resuming external LU operations (Check Paths & Restore
NOTE:
restored as the mapped LU, the external LU is set to Available. However, if the external LU is not
ready to be restored, the external LU status remains as Blocked.
The following sections describe procedures to turn the local disk array and external disk array on or off.
CAUTION: To turn off both the local disk array and external disk array, first turn off the local disk array,
and then turn off the external disk array.
CAUTION: To turn on both the local disk array and external disk array, first turn on the external disk
array, and then turn on the local disk array. If both are supplied by a common failed power source, one
option to ensure that the external disk array is online and available before the XP powers up is to place the
external disk array on an Uninterruptible Power Supply (UPS).

Turning the local disk array's power on or off

To turn off the local disk array's power

1. Stop all read and write I/O operations to the external LU that is mapped as a local disk array internal
XP LDEV.
2. Perform any other operations that are required before turning off the local disk array.
3. Turn off the local disk array's power supply.
NOTE: As you turn the local disk array's power supply off, all data for the external LU in the local disk
array's cache memory is written in the external LU (all data is destaged).

To turn on the local disk array's power

1. Turn on the external disk array that contains the external LU mapped as a local disk array internal XP
LDEV.
2. Turn on the local disk array's power.
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.
28 External Storage XP for the XP12000/XP10000
When executing the Check Paths & Restore Vol. command, if the external LU is ready to be
"Checking the connection
Vol.)" on page 87.