On 05/20/2011 06:14 PM, Christoph Hellwig wrote:
I don't quite understand what you mean with path here. It doesn't
seem to map to any SAM concept, nor does it seem to be related
to traditional multipathing.
It's what SAM calls a "bus identifier" in the description of LUN
addressing modes.
Can you explain what a path is supposed to be, and why it's called a "path"?
It's a SAM "BUS IDENTIFIER", but bus was too confusing with respect to
qdev's BusState (which represents either a SAM bus identifier or
target). I think the term "path" comes from Windows, see for example
http://msdn.microsoft.com/en-us/library/ff564699%28v=vs.85%29.aspx:
PathId [in, optional]
Indicates the SCSI port or bus for the request. This parameter is
optional.
... but I chose it because I found it also in SAM: "The BUS IDENTIFIER
field identifies the bus or path that the SCSI device shall use to relay
the received command or task management function".
I might also call it scsi-initiator which is consistent from the idea
that it sits between two targets ports.
Paolo
