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IBM DS6000 User Manual

Page 100

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76

IBM System Storage DS6000 Series: Copy Services with IBM System z

The following explanations apply to the cases presented in Example 9-1:

Example 1: 0000

0100

The FlashCopy between volume 0000 and volume 0100 is established with the property
BackgroundCopy enabled. This is the default unless specified differently using the

-nocp

parameter. All other properties are disabled. The background copy takes place
immediately. Once the copy is done, the FlashCopy relationship is automatically removed.

Example 2: 0001

0101 and 0005

0105

A FlashCopy is established between volumes 0001 and 0101 and between volumes 0005
and 0105. Both FlashCopy relationships have the same sequence number. A Consistency
Group for the two FlashCopy relationships is created using the

freeze

parameter.

BackgroundCopy is enabled—by default if not specified differently using the

-nocp

parameter. All other properties are disabled. The background copies take place
immediately for both pairs of volumes, and once the copies are completed the FlashCopy
relationships are automatically removed.

Example 3: 0002

0102

The FlashCopy between volume 0002 and volume 0102 is established with the following
FlashCopy properties enabled: Recording, Persistent, and BackgroundCopy.

The background copy takes place immediately and the relationship remains as a
persistent relationship. Using other DS CLI commands it could be reversed and/or
resynchronized.

Example 4: 0003

0103

The FlashCopy between volume 0003 and volume 0103 is established with the following
FlashCopy properties enabled: Persistent and BackgroundCopy. All other FlashCopy
properties are disabled. The background copy takes place immediately. Once the
background copy is finished the FlashCopy relationship will remain—because of the
persistent flag.

Example 5: 0004

0104

The FlashCopy between volume 0004 and volume 0104 is established with all the
FlashCopy options disabled. Due to the

-nocp

parameter, no full background copy will be

done. Only the data changed in the source is copied to the target prior to changing it. Over
time, this could result in the situation where all data is copied to the target —then the
FlashCopy relationship would end. It would also end after a background copy is initiated
using the DS SM. This way the relationship is temporarily persistent even though the
property Persistent is not activated.

Display existing FlashCopy relationships using lsflash

The command

lsflash

can be used to display FlashCopy relationships and its properties.

Parameters can be used with this command to identify the subset of FlashCopy relationships
to be displayed.

Example 9-2 on page 77 shows a script with several

lsflash

commands and the output of the

script (this script is logically based on the example for

mkflash

).

Note: The parameter

-persist

is automatically added whenever

-record

is used.