Network storage appliance with integrated redundant servers and storage controllers

A network storage appliance, comprising:

• a chassis, enclosing first and second storage controllers and first and second servers;
• said first and second storage controller, each having first and second I/O ports for coupling to first and second I/O links, each of said storage controllers configured to control a plurality of physical disk drives and to present said plurality of physical disk drives as one or more logical disk drives on said first and second I/O links;
• and
• said first and second servers, each having first and second I/O ports, said first server I/O ports for coupling to said respective first I/O link coupled to said first and second storage controller, and said second server I/O ports for coupling to said respective second I/O link coupled to said first and second storage controller, each of said servers configured to transmit to said storage controllers over said respective I/O links block-level disk commands each identifying one of said logical disk drives.

A network storage appliance, comprising:

• a chassis;
• a backplane, enclosed in said chassis, having a local bus;
• a first blade, enclosed in said chassis and coupled to said backplane, comprising a server, a first portion of a storage controller, and an I/O link coupling said server and said first portion of said storage controller;
• and
• a second blade, enclosed in said chassis and coupled to said backplane, comprising a second portion of said storage controller, said second portion of said storage controller configured to control a plurality of logical storage units;
• wherein said server is configured to transmit packets to said first portion of said storage controller over said I/O link, said packets including block-level protocol disk commands each identifying one of said logical storage units, wherein said first portion of said storage controller is configured to forward said block-level protocol disk commands to said second portion of said storage controller via said local bus.