Re: [Freeipmi-devel] Re: ipmi sensor thresholds

[Anand Babu]

,----
| FYI, I received the following from Intel:
| > The comment about undefined critical thresholds should not be a concern.  I
| > reviewed the SDR and the only sensors w/o a defined threshold are the upper
| > threshold for the fans.  This is logical since there is no reason to worry
| > about fans running too fast.  All other critical thresholds are defined.
`----
Thanks for getting this info from Intel. Now it makes sense.

   Record ID: 33
   Sensor type: F38 Tach Fan 1 (Fan)
   Sensor number: #64
   Event/Reading type code: 01h
   Lower non-recoverable threshold: 0.00 RPM
   Upper non-recoverable threshold: 0.00 RPM
   Lower Critical threshold: 2100.00 RPM
   Upper Critical threshold: 0.00 RPM
   Lower non-critical threshold: 0.00 RPM
   Upper non-critical threshold: 0.00 RPM
   Sensor min. reading: 0.00 RPM
   Sensor max. reading: 5100.00 RPM
   Normal min.: 2260.00 RPM
   Nominal reading: 2600.00 RPM
   Normal max: 2880.00 RPM
   Sensor reading: 2680.00 RPM
   Sensor status: OK

IPMI Spec says not to bother about "Normal min/max", "Sensor min/max"
readings. Because non-critical limit itself is considered as just
a warning level.

So the fields we need to look at are
   Lower non-recoverable threshold: 0.00 RPM
   Upper non-recoverable threshold: 0.00 RPM
   Lower Critical threshold: 2100.00 RPM
   Upper Critical threshold: 0.00 RPM
   Lower non-critical threshold: 0.00 RPM
   Upper non-critical threshold: 0.00 RPM
   Sensor reading: 2680.00 RPM

FAN sensor has no [Non-critical] [Non-recoverable] states.
Possible states are [OK] [Critical] [Unspecified fault].

ONLY POSSIBLE RULE IS IN THE ABOVE CASE IS:
 if (Sensor reading <= Lower Critical threshold "2100.00 RPM")
    [Critical]
 else
    [OK]

CALCULATION FOR THE ABOVE CASE:
Because "Sensor reading" (2680.00 RPM) is above "Lower Critical
threshold" (2100.00 RPM), State is [OK].

[Unspecified fault] or [Unknown] states are possible when
firmware/sensor or other failures occur.

,----[ Robin Goldstone <address@hidden> ]
| I am still a bit confused since in my mind an "undefined" threshold is
| not the same as one with value of 0.00.  Is the SDR value truly 0.00
| or is it undefined and the sensor utility just reports 0.00 in that
| case?
`----
AFIAK SDR contains 0 for these fields. I don't have a system to debug
right now. I will check the code and let you know.  

I think the correct way to do is to use other SDR cmds to find out
which fields actually contains values and which ones does not. We will
make use of these commands moving forward. libfreeipmi already has
those functions implemented.

-- 
Anand Babu
Free as in Freedom <www.gnu.org>