Powering external arrays on or off, To power external arrays off, To power external arrays on – HP StorageWorks XP Remote Web Console Software User Manual

Page 29: Writing new data to mapped external lus

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External Storage XP user guide

29

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

” on

page 98.

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.

2.

Execute the Check Paths & Restore Vol. command. For instructions, see

Checking the connection

status and resuming external LU operations (Check Paths & Restore Vol.)

” on page 100.

CAUTION:

When powering the external array off after executing the Disconnect Subsystem command,

you cannot access the mapped external LU from the local array when you initially turn on the external

array. You must execute the Check Paths & Restore Vol. command to resume using the mapped external

LU. The Check Paths & Restore Vol. command checks the defined information and the actual status of the

external LU mapped as a local array internal LDEV. 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 LU as a mapped volume.

Using mapped external LUs from the host connected to the local array

The following sections describe examples of using the mapped external LU from the host connected the

local array.

Writing new data to mapped external LUs

Figure 9

shows an example of writing new data in the mapped external LU from the host connected to the

local array.

1.

Use the External Storage XP GUI to map the LU in the external array as an internal LDEV of the local

array.

CAUTION:

You must set IO Suppression mode to Disable.

You can select the mapped volume’s emulation type as required. If you select an emulation type for an

open-system (such as OPEN-V), go to step 2. If you select an emulation type for a mainframe system

(such as 3390-3), go to step 3.
For more information, see

Mapping external LUs (Add LU)

” on page 73.

2.

For open-system emulation types (such as OPEN-V, which HP recommends), the status of the mapped

LDEV is set to Normal and is not automatically formatted. To optimally initialize the mapped LU’s data

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