Sub-file relocation

The sub-file relocation functionality relocates the data ranges of the specified files to the specified target tier. Only one instance is allowed at a time on a given node for a given mount.

You can move sub-file data by using the fsppadm subfilemove command. The application using this framework calls the fsppadm subfilemove command periodically via some external scheduling mechanism at desired intervals, to effect relocations. The application might need to call subfilemove on each node of a cluster, in case of a cluster file system, if you want to distribute the load. The application also must arrange for initiating this relocation for new mounts and reboots, if the application needs sub−file relocations on those nodes or mounts.

In a cluster situation, since enforcement can happen from multiple nodes even if each node is scheduled to collect statistics at the same intervals, each node's persistence into the database can be slightly out of sync with each other on each node. Since enforcement should follow statistics collection, Veritas recommends that you schedule enforcements on each node with a few minutes of lag so that all nodes can complete the statistics synchronizing by that time. A lag time of 5 minutes suffices in most cases.


You cannot use SmartTier to compress files while using the sub-file relocation functionality.