Subject: GLDv3 link status logging [PSARC/2007/298 Self Review]
To:      psarc-ext@sac.sfbay
Cc:      Garrett.Damore@Sun.COM
Bcc:     one-pager-list@sac.sfbay one-pager-log@sac.sfbay sac-bar@sac.sfbay


I'm submitting the following automatic case on my own behalf.  It seems
non-controversial, and only impacts syslog contents, which doesn't even seem
to be an ARC issue (logs are Not-an-interface).   The change is significant
enough that I want to give PSARC a heads up, though.  Please let me know if
there are any issues with it.


Template Version: @(#)sac_nextcase 1.58 05/23/07 SMI
This information is Copyright 2007 Sun Microsystems
1. Introduction
    1.1. Project/Component Working Name:
	 GLDv3 link status logging
    1.2. Name of Document Author/Supplier:
	 Author:  Garrett D'Amore
    1.3  Date of This Document:
	24 May, 2007
4. Technical Description

Problem
-------

Various network drivers are inconsistent in their handling of logging of
link messages.  One of the more annoying things that some drivers do is
flood the logs with link down messages (usually once every 10sec or so) when
trying to transmit packets out the link.

Further, the detailed contents for link status changes are not consistent
from one driver to another.

Notably, the WIFI drivers generally do not do this.


Solution
--------

We propose to modify GLDv3 so that GLDv3 reports (on the behalf of the driver)
when link state changes by logging a simple message to logs.  This would
only be done when the link _changes_, which could be either due to
administrative action or an external event such as a cable disconnect or
reboot or administrative action the link partner.

The message will omit all details except the state as up or down, and will
never go to the console.

The message will have one of two forms:

	nge0 link up
or 
	nge0 link down

Obviously "nge0" is for the Nvidia GigE driver.  Other drivers, etc. will
get their contents here as well.  The message will appear to come from "mac",
and will be prefixed by the normal syslog details (date, hostname, message
ID, etc.) in the system logs.

Note that side effect of this is that aggregations will also be reported to
the logs:

	"aggr0 link up"  or "aggr0 link down"

The administrator that wants more detail about the link type, mode, etc. can
use dladm to get this information. 

We will be modifying the full set of the current GLDv3 drivers to remove
any driver-specific logging of link changes.  We can do this now, while
GLDv3 is still an ON-private API.



6. Resources and Schedule
    6.4. Steering Committee requested information
   	6.4.1. Consolidation C-team Name:
		ON
    6.5. ARC review type: Automatic