[Arm-dev] Getting started / Build machines

[Gordan Bobic]

On 2014-07-30 15:17, Robert Moskowitz wrote:
> On 07/30/2014 10:05 AM, Gordan Bobic wrote:
>> On 2014-07-30 14:34, Robert Moskowitz wrote:
>>> If I better understood the build process, I would spend the $100 for
>>> another Cubie if needed.  Going to have to get another one for the
>>> server anyway.  Thing is will the C2 with 1GB memory be enough, or 
>>> the
>>> Ctruck with 2GB memory?
>> 
>> For what purpose/workload? If it is for building packages, when I
>> built RedSleeve I used 512MB Sheeva/Guru/Dream Plug machines. As
>> long as you attach plenty of swap on reasonable media (don't use
>> USB sticks or SD cards, their random-write performance is
>> _terrible_) it'll be fine. More RAM will help speed things up
>> for sure but it isn't necessary.
> 
> How do you 'attach plenty of swap'?  Attaching an SATA drive is easy
> for me and I can format it anyway I need, but how do I point swap to
> it?

man pages for fdisk, mkswap and swapon commands should tell you
what you need to know.

>> If you are asking for some kind of a server workload, it depends
>> on the workload. For example, redsleeve.org runs in a 2 GHz armv5tel
>> Marvell Kirkwood with 1GB of RAM (QNAP TS-421).
> 
> Thought so.  My C2 would be more than enough, except maybe the mail
> server.  But even it is not running all out.

How much mail do you go through? My mail server is an Atom N450
with 2GB of RAM and its performance has never been inadequate.

>> For a heavier workload you might want to look at something
>> like the Cornfed Systems' Conserver (quad core ARM, 4GB of
>> RAM, mini ITX form factor).
> 
> I am waiting to see what the Allwinner A80 will be like!

It's not all about the CPU - it's about the entire package.
Amount of RAM and form factor are, IMO, far more important
than the CPU used.

>>> I have 2 production Intel servers that I
>>> would be interested in replacing.  First my DNS server,
>>> onlo.htt-consult.com.  All it runs is DNS; I would like to get DNSSEC
>>> working at some point.  z9n9z is my mial server.  I built a C6
>>> replacement for it, but still have not rolled it out.  Minimally I
>>> would do a C7 build on the replacement hardware to check out all of
>>> the components before trying this on arm.
>> 
>> I wouldn't rush headlong into EL7 in production quite yet. Let
>> the bleeding edge adopters sort out the the most obvious issues
>> at least on x86 first.
> 
> Oh, no plan for sure!  Perhaps in late November based on Holidays and
> conferences.  I mean this month is kind of open, but more for some
> basic testing.  And some of my servers are still i686 so I have to
> wait on that too.
> 
> And I would rather spend the money replacing them with armv7 and save
> power than x86 and eat up more power!

If you're doing it for fun, that's fair enough. But if you are looking
at power saving compared to x86 on a small number of private servers,
you will find that unless your electricity costs are astronomical,
the net saving will be pennies per day compared to, say, Atom based
x86. That's not to say that Atom wouldn't suck up several times the
amount of power, but it uses little enough power to begin with that
at at, say, $0.20/KWh it'll take a long time to make a big dent on
a few small servers.

What you might want to look into is combining your various servers
using something like Linux VServer by containerizing different
tasks. My Atom N450 servers are containerized to run many different
things, e.g. mail (IMAP, SMTP, webmail), MySQL for backing those,
LDAP, OpenVPN, and probably a few other things I can't think of
right now. They were also running various other things (WordPress,
forum software) until relatively recently, but I moved those away
for other reasons (performance was never an issue).

I'm not saying don't move to ARM, I'm more saying make sure you
are doing whatever you decide to do for good reasons and based
on facts.

My public facing ARM server is this:
http://www.altechnative.net/2014/02/23/qnap-ts-421-review-modification-and-redsleeve-linux/

mainly because I needed plenty of disk space to host the primary
storage for the distro packages. Having a neat and tidy form
factor was very high on my list of priorities, so cabling sprawl
caused by all components being external was out of the question.
It wasn't a cheap option, but I am very pleased with the end
result.

Gordan