HP StorageWorks XP Remote Web Console Software - Manual (Page 28)

28 Preparing for External Storage XP operations
This command checks if defined information about the mapped external LU and the actual external LU
status match. If the external LU can be used as the mapped local array volume, the external LU is set to
accept I/O, and you can continue using the external LU as a mapped LU.
Use this command to restore the external LU, which is set to reject host I/O operations by the
Disconnect Subsystem or Disconnect Volume command, as the mapped volume. You can execute the
Check Paths & Restore Vol. command for the entire 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, see ”
Checking the connection status and resuming external LU operations (Check
Paths & Restore Vol.) ” on page 100.
NOTE: When executing the Check Paths & Restore Vol. command, if the external LU is ready to be
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 power the local and external arrays on or off.
CAUTION: To power both the local and external arrays off, first power off the local array, and then power
off the external array.
CAUTION: To power both the local and external arrays on, first power on the external array, and then
power on the local array. If both are supplied by a common failed power source, one option to ensure that
the external array is online and available before the XP powers up is to place the external array on an
Uninterruptible Power Supply (UPS).
Powering local arrays on or off
To power local arrays off
1. Stop read and write I/Os to the external LU that is mapped as a local array internal LDEV.
2. Perform other operations required before powering the local array off.
3. Turn the local array’s power off.
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
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.