Storage Foundation Cluster File System High Availability uses the SmartMove feature for thin provisioning. SmartMove enables you to migrate storage from thick storage to thin storage. SmartMove provides the ability to maintain the intent of thin provisioning.

Without SmartMove, synchronization between disks copies the entire storage that is allocated to Veritas File System (VxFS) and Veritas Volume Manager (VxVM). Synchronizing or resynchronizing a volume, plex, or subdisk can lead to unused space being allocated on the thin disk. Over time, normal operations cause the storage to become thick. With SmartMove, the disk synchronization copies only blocks that are actually in use at the file system level. This behavior prevents unused space from being allocated when a disk is synchronized or resynchronized. The disks stay thin.

The SmartMove feature is enabled for all disks by default. To take advantage of thin provisioning, SmartMove must be enabled at least for thin disks.