Patent ID: 7991972

Claim:
A computer implemented method, comprising: establishing a logical copy relationship for a logical copy operation of a source volume in a primary storage to backup as of a point-in-time, wherein during a logical copy duration, hosts have access to the source volume; maintaining a history of writes, in a computer readable storage medium, to the source volume indicating write activity to the source volume; processing the history of writes to the source volume to determine whether to allocate for a backup space for the logical copy relationship a full target volume in a secondary storage as the backup space providing a corresponding data unit for each data unit in the source volume or allocate a repository in the secondary storage as the backup space, wherein the repository uses less storage space than the full target volume; allocating the full target volume for the backup space in response to determining to allocate the full target volume; allocating the repository for the backup space in response to determining to allocate the repository; in response to allocating the full target volume, copying, during the logical copy duration, point-in-time data at the source volume to the full target volume as the backup space; in response to allocating the repository, copying, during the logical copy duration, the point-in-time data at the source volume to the repository as the backup space; and copying, during the logical copy duration, point-in-time data in the source volume at the point-in-time subject to an update during the logical copy duration to the backup space in response to receiving the update.