When a pool does not have physical capacity available to allocate new pages to TSE-VOLs, the copy operation from the CFCSE S-VOL to the CFCSE T-VOL fails when the S-VOL is updated.
Once the CFCSE relationship is in the failed state, all read and write operations to the T-VOL will fail until the relationship is released and re-established. Update operations to the S-VOL continue, but updated data is not copied to the T-VOL.
To recover an CFCSE relationship from a failed state, you must release the relationship.