Re: [PATCH v2 03/11] lpfc: Deprecate lpfc_soft_wwn parameter

[Sebastian Herbszt <herbszt@gmx.de>]

James,

thank you for taking the time to answer me.

James Smart wrote:
> Sebastian,
> 
> "not portable" isn't the right way to describe it. It's not a 
> chip-architecture issue, but rather that some oem platforms have 
> side-band management that overrides anything that could have been
> done in the os, and in ways that may not be easy to communicate back
> to the driver.

"not portable" might not be the term I actually meant. Let's call it
server vendor dependent.
Can you please elaborate on the oem platforms and side-band management
you mean? I know of a solution called "ServerView Virtual-IO Manager"
by Fujitsu which might fit. AFAIK it is a piece of software which
communicates with the BMC and allows to change the MAC address and WWN.
Of course it only works with Fujitsu servers and supported cards.
I think I heard that for NICs it just changes the MAC address in the
eeprom. This is not done "online" but when the server is powered on.
Even though this might be a comparable case (external MAC address
configuration) I think the ability to change the MAC address by the
means of "ip link set dev ethX address" was not removed.

> FAWN - true Brocade only - but that is the 70+%
> market share of the FC switches. The current implementation already
> doesn't work many situations - so there's no clear winner for having
> it work everywhere. Given the inability for it always to work, the
> decision was to deprecate the attribute.
> 
> -- james

How do you choose the desired WWN between the possible options
(factory set, oem platform set, FA-WWN)?
And wouldn't soft wwn always win because it is applied at last?
However it might compete with FA-WWN. I wasn't yet able to
find details on how it works.

Sebastian