reposting w/ the title
James Smart wrote:
Christof Schmitt wrote:
James,
i try to understand what the introduction of the vports means for
zfcp, since
this driver also supports NPIV. The documentation for the fc transport
class
describes a driver that would fully control the adapter and the
creation of
virtual address. Since you mentioned Xen, i assume that this could be
a dom0.
All true. But, there is the notion that there is a driver that thinks it's
controlling the adapter, but it's actually talking to a virtual thing, that
traps the driver's FLOGI's and turns it into FDISCs...
With zfcp, the hardware FCP adapter does NPIV and only hands out the
virtual
address to individual Linux instances. zfcp gets the assigned virtual
address
for the Linux instance. This address is used for allocating the scsi_host
structure. Basically, the whole system uses NPIV, but each Linux only
uses one
assigned virtual WWPN.
Yes - I understand. For all intents and purposes, that virtual address is
treated as an adapter.
My current understanding is that the vports introduced in the fc
transport
class do not affect the Linux systems that only use one virtual
address. To
map this to Xen, the dom0 would use the vports to show all virtual
address, and
each domU would use the assigned virtual address without showing the
vport in
sysfs. Is this correct?
Christof
Agreed. It should mean nothing to the zfcp driver. Nothing changes in
the driver
if it will always be a single address.
Although - if your hardware-to-driver interface had the ability to
instantiate
a new address, you could augment your driver to support the vport calls.
That's
a choice for you though.
-- james
PS: One thing I didn't call out in the vport patches was the expectation
that
the vport-supporting driver had to set the PPN attribute appropriately.
And... did you see that T11 is trying to change what the PPN is set to
- the
fabric port_name not the physical N_Port port_name.
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