lm_sensors vs. IPMI

Mark Studebaker mds4 at verizon.net
Fri Mar 5 03:30:10 CET 2004

I can elaborate.

Our modules bmcsensors and i2c-ipmi, together, connect the lm-sensors userspace tools to IPMI,
so that you can do the usual things you can do with lm-senssors (see temperatures, voltages, and fan speeds,
set limits, and see alarms). If this is what you need, lm-sensors will do it.

IPMI is a quite sophisticated interface, and it is capable of much more than what
is available through the lm-sensors interface (for example, event logging).

I'm sure there are many other programs available to use IPMI. Some of these certainly
will expose more of the richness of IPMI.

The third module is i2c-ipmb. This was meant to export the raw i2c busses behind the
BMC controller to the kernel. You could make the argument that this isn't a good idea.
But in any case, the BMC I have doesn't support the messages required for i2c-ipmb,
so I never got it working.

To the extent that board makers are adding BMC controllers to boards, and putting
the hardware monitors behind the BMC, this makes the direct hardware monitor drivers
that make up the bulk of lm-sensors unnecessary. In that case, you must use IPMI.
But you still need additional modules and/or userspace apps that talk IPMI to get
the data out. That's where you are welcome to try our solution
(sensors->libsensors->bmcsensors->i2c-ipmi->IPMI->BMC->the chips)
or another program on top of IPMI.

Hope this helps.
Give our package a try if you like.


Jean Delvare wrote:
>>I've seen several postings claiming that lm_sensors is out and IPMI is
>>in.  Do they serve the same purpose?  I played with IPMI a few months
>>back and never got anything out of it.
> I admit my relative ignorance in that domain. Yes, I think they serve
> the same purposes. I think we even have a non-working ipmi driver that
> is supposed to establish a bridge between both realms. Never gave it a
> try so far, however, since I don't have any hardware using this. I guess
> it's meant for relatively high-end servers only.

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