A preferred embodiment of the present invention is described in detail below. However, the present invention can be widely applied in embodiments other than those described in the detailed description, and the scope of the present invention is not limited by the embodiment, but is defined by the appended claims.
The present invention discloses a bridging apparatus for bridging a host to a SAN, and the bridging apparatus is capable of virtualizing a disk volume allocated in the SAN as a DAS drive. Through a DAS interface, e.g. SCSI, USB, SAS or SATA with support of port multiplier, the host can attach multiple virtual DAS drives simultaneously. The bridging apparatus comprises: a first HBA for connecting to a SAN, a second HBA for connecting to a host having a DAS interface, a bridge controller for connecting to the first HBA and the second HBA, respectively, so as to bridge the host to the SAN, thereby allowing the host to directly access a disk volume allocated in the SAN, and a storage unit connecting to the bridge controller for storing program and data.
The foregoing DAS HBA 110 may connect to one of the SCSI, SATA (Serial ATA), eSATA (External SATA), USB or SAS (Serial Attached SCSI) interfaces. However, persons skilled in the art know that the accomplishment of the present invention should not be limited by the above interfaces.
Further, the bridging apparatus 100 includes a flash memory 140 and a DRAM 120 respectively connecting to the bridge controller 130. The DRAM 120 is used to be a cache memory of the disk volume for the SAN so as to speed up access to the SAN, and the flash memory 140 is used to store programs and data needed by the bridge controller 130.
The bridging apparatus of the present invention may simplify connecting from a DAS to a SAN and provides the following advantages: 1) Plug-and-play without additional driver. 2) Hosts connecting to the SAN may boot-up through a disk volume allocated in the SAN without additional boot ROM. Since a disk volume of the SAN is assigned to a host connecting to the SAN via the bridging apparatus of the present invention, the host may boot-up without any local disk. In fact, the host will deem the disk volume allocated in the SAN as a local disk. 3) Therefore, the host connecting to the SAN may directly access the volume disk allocated in the SAN as accessing a local disk. 4) The host connecting to the SAN via the bridging apparatus of the present invention does not need any local disk. Instead, a storage space in the SAN will be assigned to the host connecting to the SAN, such that IT persons may centralize managing and allocating disk spaces for hosts connecting to the SAN. 5) In addition, the bridging apparatus of the invention may be used in different platforms.
The above description is only a preferred embodiment of the present invention, and not used to limit the claims of the present invention. All equivalent variations or modifications performed without departing from the spirit disclosed in the present invention are within the following claims.