Computer Drive User Manual

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.