COMSTAR: Common Multiprotocol SCSI Target
By Eric Kozlowski-Oracle on Jan 28, 2008
One of the new Solaris Storage projects that our test development team is currently implementing test infrastructure for is called COMSTAR. The overview of the project from the OpenSolaris.org COMSTAR page is:
COMSTAR is the software framework to use a Solaris host as a SCSI Target platform. COMSTAR uses modular approach to break the huge task of handling all the different pieces in a SCSI target subsystem into independent functional modules which are glued together by the SCSI Target Mode Framework (STMF). The modules implementing functionality at SCSI level (disk, tape, medium changer etc.) are not required to know about the underlying transport. And the modules implementing the transport protocol (Fibre Channel, iSCSI etc.) are not aware of the SCSI level functionality of the packets they are transporting. The framework hides the details of allocation, providing execution context and cleanup of SCSI commands and associated resources and simplifies the task of writing the SCSI or transport modules.
COMSTAR features include:
- Extensive LUN Masking and mapping functions.
- Multipathing across different transport protocols.
- Multiple parallel transfers per SCSI command.
- Scalable design approach.
- Works with generic HBAs.