Techniques for providing storage array services to a cluster of nodes using portal devices

A storage array, comprising:

• a host interface configured to communicate with an external host;
• a local storage device coupled to the host interface;
• and
• a portal device coupled to the host interface, the portal device including local circuitry configured to communicate with (i) the external host though the host interface and (ii) a remote storage device through an external communications pathway, the portal device being configured to behave as a local disk to the external host to enable the external host to perform data mirroring operations on the local storage device and the portal device through the host interface.

In a local storage array having a host interface, a local storage device and a portal device, a method for providing storage array services to an external host participating as a node of a cluster of nodes, the external host being configured to operate as a cluster volume manager (CVM), the method comprising:

• establishing a communications pathway from the portal device to a remote storage device of a remote storage array;
• within the portal device, temporarily buffering write operations from the external host, the portal device being configured to behave as a local disk to the external host to enable the CVM to perform data mirroring operations by providing a local write instruction to the local storage device through the host interface and remote write instruction to the portal device through the host interface, the local write instruction and the remote write instruction (i) being separate and independent, (ii) including the same data and (iii) being provided through the host interface in a substantially contemporaneous manner;
• and
• forwarding the temporarily buffered write operations from the portal device to the remote storage device through the established communications pathway.