Christoph, FYI - Emulex is committed to completing the effort for creating a vendor-agnostic open-source hbaapi library for linux, including the thornier issues of performing CT passthru and RNID functionality. As soon as the library exists, an open-source SMI-S provider would become available as well. -- James > -----Original Message----- > From: linux-scsi-owner@xxxxxxxxxxxxxxx > [mailto:linux-scsi-owner@xxxxxxxxxxxxxxx]On Behalf Of > Christoph Hellwig > Sent: Monday, April 18, 2005 11:40 AM > To: linux-scsi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Subject: Fibre Channel state of the union > > > > With the upcoming merge of the current SCSI development > branch (probably > after the 2.6.12 release), Linux will have more advanced Fibre Channel > support than any currently available operating system. > > The new Fibre Channel (FC) transport class offers two major advantages > over traditional standalone drivers: > > (1) It provides an easy to use library to deal with most > aspects of FC > remote port management and its integration into SAM and the Linux > SCSI layer. > > - a remote port object that sits between the host and the target > in the Linux SCSI layer object model > - support for remote port based LUN scanning, including live > rescanning on fabric topology changes and stable remove port to > SCSI target id mappings > - a queue freeze facility to handle temporary cable > unplugs without > generating I/O errors > > (2) a common userspace interface to transport specific and management > information in sysfs. The information provided is based > on a sane > subset of the SNIA HBA API specification. > > This reduces the burden of writing and maintaining an FC HBA driver > substantially, for example the recent conversion of the > qla2xxx driver to > use these facilities removes over 3000 lines of code (about > 1/5 of the overall > driver size) while adding new features and a userspace > management interface. > The FC transport class thus allows hardware vendors to concentrate on > interfacing with the hardware and support their unique > features, freeing > them from the burden of reimplementing basic infrastructure > in every driver > and designing ad hoc management interfaces. > > We now have two drivers supporting this infrastructure fully: > > - qla2xxx for Qlogic 2100/2200/23xx HBAs > - lpfc for all Emulex SLI2 HBAs > > Two drivers for modern hardware don't fully use this > infrastructure yet, > but we are working with the maintainers and expect the drivers to be > updated to take advantage of the new FC transport class soon. > > - zfcp for the Fibre Channel attachment on the IBM zSeries > mainframes > - mptfusion for the LSI "Fusion" 909/919(X)/929(X) HBAs > > Still missing is an Open Source tool application utilizing our APIs. > The currently available proprietary applications are > inflexible, available > only for very few of the architectures supported by Linux, and tied to > specific HBAs. The common API and hardware independence > provide a great > opportunity for the Hardware vendors to collaborate on a > single Open Source > management application and leverage the cost savings of an > open development > method. > > We are also looking forward to a bridge from the Linux > management interfaces to the "industry-standard" SNIA HBA API, > allowing various management applications to work out of the > box with our > stack. > > To make these new features available to Enterprise users and > reduce the > fragmentation in driver and management space we will be > working with the > major players in the Storage Industry and the Linux > Distribution vendors > to support and certify this stack in the near future. > > Special thanks go to Emulex and James Smart in particular for > implementing > the majority of the new Fibre Channel transport class. We > also want to > thank Andrew Vasquez at Qlogic for providing valuable input on the > transport class design and for updating the qla2xx driver to > use the new > facilities quickly. > > The Linux SCSI community plans to provide a similar framework for > Serial Attached SCSI (SAS) transports in the near future. > > > Thanks to Arjan van de Ven, Peter Jones, Randy Dunlap, Rik van Riel, > Nikita Danilov and James Bottomley for reviewing this document and > suggesting various improvements. > - > : send the line "unsubscribe > linux-scsi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
