Abstract: A technique controls a network switch having a set of ports. The technique involves configuring the network switch to provide an initial set of communications paths between the ports. The initial set of communications paths defines an initial communications path topology within the network switch. The technique further involves receiving a configuration command which identifies a particular operating mode of the data storage system after configuring the network switch to provide the initial set of communications paths within the network switch. The technique further involves reconfiguring the network switch to provide a new set of communications paths between the ports in response to the configuration command. The new set of communications paths (i) defines a new communications path topology within the network switch, the new communications path topology being different than the initial communications path topology, and (ii) supports the particular operating mode of the data storage system.

Abstract: A computerized system includes two storage processors having respective local write caches configured to mirror each other. When a first storage processor becomes unavailable and mirroring of the local write caches is prevented, the computerized system continues to attend to write operations from an external host in a write-back manner by caching write data from the write operations in the local write cache of the second storage processor. In response to a failure of the second storage processor, the computerized system preserves the write data within the local write cache of the second storage processor. Then, upon recovery of the second storage processor from the failure, the computerized system continues to attend to further write operations from the external host in the write-back manner by caching additional write data in the local write cache of the second storage processor while the first storage processor remains unavailable.

Abstract: A data storage system includes a storage processor that is configured to perform load and store operations on a storage array on behalf of external devices. The data storage system also includes a controller that isolates communication between the external devices when coupled to the storage array via the storage processor. The controller further maintains a set of registers that store information associated with the data storage system and allows the storage processor to access the register via an I2C bus. The system utilizes an error detection procedure to allow detection of errors in the data transmitted between the controller and the storage processor. During operation, a checksum value is transmitted between the controller and the storage processor using the I2C bus during a register write or read procedure. The controller and the storage processor utilize the checksum value in an error detection procedure to detect the data errors resulting in transmission of the data by the I2C bus.

Abstract: A computerized system includes two storage processors having respective local write caches configured to mirror each other. When a first storage processor becomes unavailable and mirroring of the local write caches is prevented, the computerized system continues to attend to write operations from an external host in a write-back manner by caching write data from the write operations in the local write cache of the second storage processor. In response to a failure of the second storage processor, the computerized system preserves the write data within the local write cache of the second storage processor. Then, upon recovery of the second storage processor from the failure, the computerized system continues to attend to further write operations from the external host in the write-back manner by caching additional write data in the local write cache of the second storage processor while the first storage processor remains unavailable.

Abstract: A data storage system includes a storage processor that is configured to perform load and store operations on a storage array on behalf of external devices. The data storage system also includes a controller that isolates communication between the external devices when coupled to the storage array via the storage processor. The controller further maintains a set of registers that store information associated with the data storage system and allows the storage processor to access the register via an I2C bus. The system utilizes an error detection procedure to allow detection of errors in the data transmitted between the controller and the storage processor. During operation, a checksum value is transmitted between the controller and the storage processor using the I2C bus during a register write or read procedure. The controller and the storage processor utilize the checksum value in an error detection procedure to detect the data errors resulting in transmission of the data by the I2C bus.