Discussions of the use of NetBSD in embedded systems

Andy Ball | 10 Jul 2012 14:46

Paring down NetBSD


Hello Dave,

  DPM> I run lots of NetBSD machines, but they're all
     > "production" roles, usually as firewalls and routers,
     > mostly at customer sites but one here.

    Do you pare down your router/firewall installations?
What are you able to omit Vs. an ordinary NetBSD server
installation?

  DPM> I use sparc64 (Netra X1s mostly...tiny, cheap, low
     > power) for that stuff.

    I understand those are quite energy-efficient. RAM might
be quite expensive if you don't already have it laying
around though.  I think the only SPARC hardware I have left
is a Krupps that I would like to configure as an X terminal.
I need to learn how to net-boot it though and how to tailor
a NetBSD image for a diskless environment (for this and
other embedded applications).

-Andrew Ball

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Lloyd Parkes | 11 Jul 2012 01:25

Re: Paring down NetBSD

On 11/07/2012, at 12:46 AM, Andy Ball wrote:
>    Do you pare down your router/firewall installations?
> What are you able to omit Vs. an ordinary NetBSD server
> installation?

I don't know about Dave, but I usually just throw base.tgz and etc.tgz on embedded boxes. Modern storage has
outgrown base.tgz so much that it normally isn't worth the mental effort of stripping a system down any further.

>  DPM> I use sparc64 (Netra X1s mostly...tiny, cheap, low
>> power) for that stuff.
> 
>    I understand those are quite energy-efficient.

That is almost certainly not true. Power requirements for any given unit work of are dropping all the time,
so it isn't hard to get new hardware that will be much more efficient than old hardware. By efficient, I mean
CPU throughput per watt, although power supply efficiency is also improving. Last year I finally bit the
bullet and replaced a small bunch of sparc64 and i386 boxes with a single Xen server. Everything runs
faster, my electricity bill went down and that room is no longer the warmest room in the house. If it will do
the job, just buy an Intel Atom.

> I need to learn how to net-boot it though and how to tailor
> a NetBSD image for a diskless environment (for this and
> other embedded applications).

I have a system for building images to do that at
http://home.must-have-coffee.gen.nz/hg/software/miniaturise/. It does have a couple of flaws: 1)
it can use syspkgs, but syspkgs isn't structured in a way that is very useful, 2) the configuration file
format is at best OK. Now that I'm self-employed, I'll be putting some time onto working on that software
some more.

(Continue reading)

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Andy Ball | 11 Jul 2012 14:24

Re: Paring down NetBSD


Hello Lloyd,

  LP> I don't know about Dave, but I usually just throw
    > base.tgz and etc.tgz on embedded boxes. Modern storage
    > has outgrown base.tgz so much that it normally isn't
    > worth the mental effort of stripping a system down any
    > further.

    What about configuration: Do you turn down the logging
or do anything to stop NetBSD mailing root every day?

  LP> That is almost certainly not true. Power requirements
    > for any given unit work of are dropping all the time,
    > so it isn't hard to get new hardware that will be
    > much more efficient than old hardware. By efficient,
    > I mean CPU throughput per watt...

    I understand what you're saying and clearly it will
depend what you're comparing the machine against.  Older
light servers can sometimes be useful as edge devices
where you want one device to do specific light-duty
work: In the past I've used them for print servers and I
currently run a Pentium III (burns <30 Watts) as a
terminal server, providing SSH access to an HVAC system
and logging data from a PABX. When that machine fails it
would make sense to replace it with an embedded board
but until then I can't justify the expense.

-Andy Ball

(Continue reading)

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Lloyd Parkes | 12 Jul 2012 02:23

Re: Paring down NetBSD

On 12/07/2012, at 12:24 AM, Andy Ball wrote:

>   What about configuration: Do you turn down the logging
> or do anything to stop NetBSD mailing root every day?

I just syslog everything to a central server (on the same LAN). I looked at putting on an embedded mailer, but
I couldn't find one, so I just left postfix running and I forward root to mail to the same central server that
receives the syslog records. I think that box has postfix and the daily emails turned off because mostly
what I get are pkgsrc vulnerability messages and that box doesn't have any additional packages on it.

> currently run a Pentium III (burns <30 Watts) as a

That's the magic. You've measured your power consumption. 

Cheers,
Lloyd