Chapter 11. Advanced Copy Services 437
When FlashCopy is used for backup purposes, the target data usually is managed as 
read-only at the operating system level. This approach provides extra security by ensuring 
that your target data was not modified and remains true to the source.
Restore with FlashCopy
FlashCopy can perform a restore from any FlashCopy mapping. Therefore, you can restore 
(or copy) from the target to the source of your regular FlashCopy relationships. When 
restoring data from FlashCopy, this method can be qualified as reversing the direction of the 
FlashCopy mappings.
This capability has the following benefits:
/SM590000There is no need to concern about pairing mistakes. You trigger a restore.
/SM590000The process appears instantaneous.
/SM590000You can maintain a pristine image of your data while you are restoring what was the 
primary data.
This approach can be used for various applications, such as recovering your production 
database application after an errant batch process that caused extensive damage. 
In addition to the restore option, which copies the original blocks from the target volume to 
modified blocks on the source volume, the target can be used to perform a restore of 
individual files. To do that, you need to make the target available on a host. Is suggested to do 
not make the target available to the source host because seeing duplicates of disks causes 
problems for most host operating systems. Copy the files to the source by using normal host 
data copy methods for your environment.
For more information about how to use reverse FlashCopy, see 11.1.12, “Reverse FlashCopy” 
on page 457.
Moving and migrating data with FlashCopy
FlashCopy can be used to facilitate the movement or migration of data between hosts while 
minimizing downtime for applications. By using FlashCopy, application data can be copied 
from source volumes to new target volumes while applications remain online. After the 
volumes are fully copied and synchronized, the application can be brought down and then 
immediately brought back up on the new server that is accessing the new FlashCopy target 
volumes.
This method differs from the other migration methods, which are described later in this 
chapter. Common uses for this capability are host and back-end storage hardware refreshes.
Application testing with FlashCopy
It is often important to test a new version of an application or operating system that is using 
actual production data. This testing ensures the highest quality possible for your environment. 
FlashCopy makes this type of testing easy to accomplish without putting the production data 
at risk or requiring downtime to create a constant copy. 
Preferred practices: Although restoring from a FlashCopy is quicker than a traditional 
tape media restore, you must not use restoring from a FlashCopy as a substitute for good 
backup/archiving practices. Instead, keep one to several iterations of your FlashCopies so 
that you can near-instantly recover your data from the most recent history, and keep your 
long-term backup/archive as appropriate for your business.