Chapter 11. Advanced Copy Services 461
11.1.15  Thin provisioned FlashCopy 
FlashCopy source and target volumes can be thin-provisioned. 
Source or target thin-provisioned 
The most common configuration is a fully allocated source and a thin-provisioned target. By 
using this configuration, the target uses a smaller amount of real storage than the source. 
Start When all of the FlashCopy mappings in a Consistency Group are in the 
prepared state, the FlashCopy mappings can be started. To preserve the 
cross-volume Consistency Group, the start of all of the FlashCopy 
mappings in the Consistency Group must be synchronized correctly 
concerning I/Os that are directed at the volumes by using the startfcmap 
or startfcconsistgrp command. 
The following actions occur during the running of the startfcmap 
command or the startfcconsistgrp command:
/SM590000New reads and writes to all source volumes in the Consistency 
Group are paused in the cache layer until all ongoing reads and 
writes beneath the cache layer are completed. 
/SM590000After all FlashCopy mappings in the Consistency Group are paused, 
the internal cluster state is set to enable FlashCopy operations. 
/SM590000After the cluster state is set for all FlashCopy mappings in the 
Consistency Group, read and write operations continue on the 
source volumes.
/SM590000The target volumes are brought online.
As part of the startfcmap or startfcconsistgrp command, read and 
write caching is enabled for the source and target volumes. 
Modify The following FlashCopy mapp ing properties can be modified:
/SM590000FlashCopy mapping name
/SM590000Clean rate
/SM590000Consistency group
/SM590000Copy rate (for background copy or stopping copy priority)
/SM590000Automatic deletion of the mapping when the background copy is 
complete
Stop The following separate mechanisms  can be used to stop a FlashCopy 
mapping: 
/SM590000Issue a command 
/SM590000An I/O error occurred 
Delete This command requests that the specified FlashCopy mapping is 
deleted. If the FlashCopy mapping is in the copying state, the force flag 
must be used. 
Flush failed If the flush of data from the cache cannot be completed, the FlashCopy 
mapping enters the stopped state. 
Copy complete After all of the source data is copied to the target and there are no 
dependent mappings, the state is set to copied. If the option to 
automatically delete the mapping after the background copy completes is 
specified, the FlashCopy mapping is deleted automatically. If this option 
is not specified, the FlashCopy mapping is not deleted automatically and 
can be reactivated by preparing and starting again. 
Bitmap online/offline The node failed. 
Mapping event Description