A method for data storage, including configuring a first logical volume on a first storage system and a second logical volume on a second storage system. The second logical volume is configured as a mirror of the first logical volume, so that the first and second logical volumes form a single logical mirrored volume. The method also includes receiving at the second storage system a command submitted by a host to write data to the logical mirrored volume, and transferring the command from the second storage system to the first storage system without writing the data to the second logical volume. On receipt of the command at the first storage system, the data is written to the first logical volume. Subsequent to writing the data to the first logical volume, the data is mirrored on the second logical volume.