iSCSI

Abstract: A network interface device connected to a host provides hardware and processing mechanisms for accelerating data transfers between the host and a network. Some data transfers are processed using a dedicated fast-path whereby the protocol stack of the host performs no network layer or transport layer processing. Other data transfers are, however, handled in a slow-path by the host protocol stack. In one embodiment, the host protocol stack has an ISCSI layer, but a response to a solicited ISCSI read request command is nevertheless processed by the network interface device in fast-path. In another embodiment, an initial portion of a response to a solicited command is handled using the dedicated fast-path and then after an error condidtion occurs a subsequent portion of the response is handled using the the slow-path. The interface device uses a command status message to communicate status to the host.

Abstract: A storage object such as a virtual disk drive or a raw logical volume is contained in a UNIX compatible file so that the file containing the storage object can be exported using the NFS or CIFS protocol and shared among UNIX and MS Windows clients or servers. The storage object can be replicated and backed up using conventional file replication and backup facilities without disruption of client access to the storage object. For client access to data of the storage object, a software driver accesses the file containing the storage object. For example, a software driver called a virtual SCSI termination is used to access a file containing a virtual SCSI disk drive. Standard storage services use the iSCSI protocol to access the virtual SCSI termination. An IP replication or snapshot copy facility may access the file containing the virtual SCSI disk drive using a higher-level protocol.

Abstract: The present invention is generally directed to a system and method for virtualizing storage in a networked system. In accordance with one aspect of the invention, in a system having an initiator and at least one storage device, an inventive method determines, based upon a SCSI command received by a manager from the initiator, which of the data storage devices are implicated by the SCSI command. The method then forms an iSCSI command that is sent from the manager to each of the implicated storage devices, and receives at the manager an iSCSI response from each of implicated storage devices, after each of the storage devices has completed its implicated data transactions with the initiator. Finally, the method forms a SCSI response that is sent by the manager to the initiator. A corresponding system is also provided.

Abstract: Storage gateway remote and local access to storage devices is provided in part via a target implementing bandwidth-controlled access to the devices. The target may be iSCSI-compatible, and may also optionally implement protection, security, and performance features. The protection and security features include any combination of VLANs, zoning, Logical Unit Number (LUN) masking, and encryption. The performance features include any combination of HW-accelerated Remote Direct Memory Access (RDMA), prioritized I/O operations, and service priority (such as strict priority and straight or weighted round-robin priorities). An initiator may be implemented in a Processor Memory Module (PMM) coupled to a switch fabric that is in turn coupled to a target implemented in a Fibre Channel Module (FCM). Storage traffic may be communicated as Small Computer System Interface (SCSI)- and SCSI over Transmission Control Protocol/Internet Protocol (iSCSI)-compatible information (data and commands) on the switch fabric via cellifying input/output interface devices.