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Re: [OCLUG-Tech] Plug Computers

On 11-01-30 09:47 PM, Paul B. wrote:
> I've been waiting for the ARM revolution to hit my home, and I'm now 
> wondering if it's here.

The ARM revolution is here, but it is not much of a revolution. There
are many black box consumer products with ARM (and MIPS). Many of these
you can jam Linux on. I don't think we will see a real revolution until
we can easily buy more general purpose ARM boxes.

I have a guruplug server plus from GlobalScale. It seems to be
discontinued which is a good thing. The GuruPlug ServerPlus has a bad
design and easily overheats. The replacement, the DreamPlug, looks good


You will also need a way to connect to the 5v serial port. The GuruPlug
JTAG is overkill, but works. (Unless you hack micro-controllers you
probably don't have any low voltage serial adapters and will likely want
the GuruPlug JTAG adapter.)


The Guruplug is an open platform in that you can (and are encouraged to)
install your own OS and software. It was fairly easy to install Debian
Squeeze. Debian/Lenny does not fully support the GuruPlug. There are
several guides a google search away. Most reference the Debian developer
Martin Michlmayr's site:


I read several sites, tried to understand what they were doing and
developed my own process. Sadly I have misplaced my notes. :(

Almost everything that applies to the SheevaPlug applies to the
Guruplug. The big difference is the arcNumber which is 2659 for the
GuruPlug. The annoying differences are in the features supported by the
boot firmware. The boot firmware I use does not properly support loading
the kernel from USB or SD card. Fortunately there are guides for the
Sheeva and Guru plugs that show how to load the kernel from a tftp
server and save the image in the flash.

You will want a tftpd server. I use tftpd-hpa.

> I've got a box in the basement that I'm pretty sure could be replaced by 
> one(!) of these things. 

You could use one Guruplug or DreamPlug for BIND, DHCP, NTP, Firewall,
and IMAP. The cpu is up to the task (openwrt on a 200MHz MIPS can handle
the first four at least). The only task you might have issues with the
IMAP. I found the eSATA speed to be terrible. I was lucky to read faster
then 10Mbyte/s.  It is the reason I didn't replace my home server (IMAP,
SMTP, Samba, and NFS) with my GuruPlug.

I ran those tests back in June. Now that Squeeze is almost out I should
upgrade everything and run the tests again. From the spec sheets the
performance should have been better.

And don't get too excited by the claims of 5 watts. Measured at the wall
mine draws 10 watts plus, and 20 watts with hard drives. The claim of 5
watts is probably after conversion to DC and without network or wireless.

The ARM plugs are fun to play around with and a good learning
experience. In terms of a home server there is not a whole lot of value
(IMHO). The 'plugs are really prototype platforms aimed at designers
working on commercial products like the PogoPlug, and many of the home
NAS boxes. For similar amounts of money (or less) you could get an AMD
Sempron 140, or Intel Atom system that will draw 30 watts are less at
idle, and provide a whole lot more performance, and be easier to work with.