Unmapping logical block addresses of remote asynchronously replicated volumes

An apparatus comprising:

• a first storage array comprising at least one compute node that manages access to a first array of drives, the first storage array configured to be responsive to receipt of an unmap command from a host server indicating a range of logical block addresses of a local replica of an asynchronously replicated storage object for which a remote replica exists on a second storage array to:
• create an unmap extent corresponding to the unmap command;
• and
• transmit the unmap extent from the first storage array to the second storage array with extents of replication data.

A non-transitory computer-readable storage medium storing instructions that when executed by compute nodes in a storage system perform a method comprising:

• receiving an unmap command by a first storage array from a host server, the unmap command indicating a range of logical block addresses of a local replica of an asynchronously replicated storage object for which a remote replica exists on a second storage array;
• creating an unmap extent corresponding to the unmap command;
• and
• transmitting the unmap extent from the first storage array to the second storage array with extents of replication data.