Solaris FibreChannel Stack

On opensolaris-storage, there have been some discussions about the Solaris FibreChannel stack. Here's a pretty good picture of how it fits together.  From the top:

1. Fibre Channel HBA-API and Multi Path API are industry standard ways to communicate with storage software. luxadm and cfgadm are utilities to control and report status on storage.
2. sd/st/ses are SCSI target drivers.  Target drivers in Solaris are a driver to control a particular type of SCSI peripheral. We'll talk about IP/ARP and the other networking portions later.
   
3. SCSA is thin layer that connects HBAs and target drivers
4. MPXIO is the Solaris multipathing solution. It allows for several physical paths to one device, for fault tolerance and higher performance.
5. FCP is the SCSI to FibreChannel layer. FCSM is a small device driver for management applications. FCIP is network device driver, which allows IP over FibreChannel
   
6. FC Transport is the fctl and fp device drivers.  This keeps track of which ports are where. It also generally does the FP-2 protocol, handling device discovery and changes in the SAN.
   
7. At the bottom, we have each vendor's specific library, to run their particular HBA.
8. On the right is FibreChannel doing networking.  FibreChannel was designed as a general purpose transport. As well as SCSI, it can carry TCP/IP networking protocol, and Solaris supports IP over FibreChannel.
   
9. On the bottom left are the FibreChannel drivers that run without the Solaris FibreChannel stack.