Re: [LUAU] Anyone use a Linksys NSLU2? USB hard disk drives are FOSSfriendly?

[David Kiwerski]

R. Scott Belford wrote:

Brian Chee wrote:
My biggest bitch about "normal" machines is that I want my NAS up all 
the

time and a 350watt power supply could potentially add something like
$20/month to my electric bill


As a partial aside - if a power supply is rated at 350 watts, does 
this mean that it constantly pulls 350 watts?  If so, I may need to do 
a costs-benefits analysis of my own pc based file servers.



/brian chee


--scott
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No, a 350 watt power supply won't draw 350 watts constantly.   There is 
a minimum current draw for the supply, even when idle.   Also, remember 
that the "350 watts" refers to the total output of the supply.   Most 
supplies are 60 to 90% efficient, so the actual current draw would be 
greater than the output specification.   For instance, the Seagate 750Gb 
SATA-2 drives draw 12.6 watts during seek, read and write operations 
(this according to their specs).   The motherboard/cpu compination draws 
a certain amount of power.   One can figure out pretty closely what the 
actual power usage is for a particular computer setup.


DaveK

 


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RE: [LUAU] Anyone use a Linksys NSLU2? USB hard disk drives are FOSSfriendly?

[Brian Chee]

Yet more stuff for the home micro machine builder.nice collection of
hard to find super small machines...

http://linuxdevices.com/articles/AT2016997232.html

Keep in mind that the N!C (new internet computer) is no longer available.
HOSEF snagged a whole bunch from me a while back...they're cdrom based and
slow, but do have an IDE controller on the via motherboard so adding a 2.5
disk would make it a pretty reasonable small machine...I believe scott and
company are using then as thin clients for the LTSP stuff...

/brian chee


InfoWorld Media Group c/o
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2525 Correa Road, HIG 500
Honolulu, HI 96822
Tel: 808-956-5797, Fax: 877-284-1934

-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Jim Thompson
Sent: Wednesday, December 27, 2006 9:47 PM
To: LUAU
Subject: Re: [LUAU] Anyone use a Linksys NSLU2? USB hard disk drives are
FOSSfriendly?


On Dec 27, 2006, at 6:33 PM, R. Scott Belford wrote:

> Jim Thompson wrote:
>
>> You might conclude that I'm considering building a product around  
>> all this.   About 70% of what I'm thinking is in this thread
>>>> http://www.intel.com/design/servers/storage/ss4000-E/
>
> This runs a Linux kernel.  Is it a m0no0wall derivative rather than  
> being based on freeNAS?

Yes, the product I pointed to, *as shipped*, runs linux.

You can think of 'm0n0wall' as a specialized FreeBSD "distro" for  
networking hardware.FreeNAS is a 'spin' of m0n0wall focused on  
supporting fileservers, rather than routers/firewalls/Access Points.

For this application, I prefer FreeBSD over Linux.  There are many  
reasons.

For one thing, the ZFS support is further along, and Linux's "FUSE"  
architecture (necessary to adopt ZFS on linux, because ZFS isn't  
(yet?) licensed under a GPL-compatible license, so FUSE is used to  
keep the ZFS code in user-space), is never going to be 'fast'.

For another, FreeBSD's "Geom" architecture, so GELI and GDBE become  
options.   Now if you note that I explained that I'd found a board  
with an on-board HiFn crypto accelerator, (one that just happens to  
already be supported by FreeBSD's "crypt' framework (supported by  
GELI)), you can probably put the pieces together.  :-)   GELI also  
has some interesting 'features' that allow me to market a key  
recovery service.

Putting FreeBSD, ZFS (and a variant of FreeNAS) on the product  
involves some work, its true.

But I think I get a better product out of it than just sticking  
FreeNAS on a PC.

And remember, the hardware I'm buying is identical to that marketed  
by Intel, but I don't pay Intel's "uplift" (nor the channel margin)  
seen in the $560 price.

Jim
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RE: [LUAU] Anyone use a Linksys NSLU2? USB hard disk drives are FOSSfriendly?

[Brian Chee]

Just FYI on this thread, I just got my new Astrodyne power supply catalog
and wall warts and inline power supplies run from 12watts up to 130watts and
can output from as low as 2.5volts up to 48volts (amperages vary upon
voltage, natch)

http://www.astrodyne.com

They also have some VERY nice DC to DC converters that I've used for the
PODS project...the cool part is that one of the pins controls output so you
don't need an additional relay for power control. We used a basic stamp that
used a 1 farad capacitor as a battery (10 hours and could be charged from a
2"x2" photovoltaic) that would then power on (using this control pin) the
power hungry (relative) larger general purpose embedded Linux SBC that
controlled our environmental sensors (Dallas Semiconductor 1-wire system),
high res digital cameras (gPhoto) and radios.

The nice thing is that these guys don't have problems with quan 1 orders and
also provide engineering drawings for the pin patterns and such. Some of the
inline switching power adapters can also provide multiple outputs like
5V/12V which is super handy for SBC computers.

P.S. they also have a large variety of DIN rail power supplies...for my home
server I'm contemplating a DIN rail machine if I can find one that isn't too
expensive...perhaps I could make/find a case for the SOEKRIS board that is
superb and has encryption modules on some models. (not to mention no cross
compilers since SOEKRIS is Intel compatible)

/brian chee


InfoWorld Media Group c/o
University of Hawaii SOEST (ANCL)
2525 Correa Road, HIG 500
Honolulu, HI 96822
Tel: 808-956-5797, Fax: 877-284-1934

-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Jim Thompson
Sent: Wednesday, December 27, 2006 9:47 PM
To: LUAU
Subject: Re: [LUAU] Anyone use a Linksys NSLU2? USB hard disk drives are
FOSSfriendly?


On Dec 27, 2006, at 6:33 PM, R. Scott Belford wrote:

> Jim Thompson wrote:
>
>> You might conclude that I'm considering building a product around  
>> all this.   About 70% of what I'm thinking is in this thread
>>>> http://www.intel.com/design/servers/storage/ss4000-E/
>
> This runs a Linux kernel.  Is it a m0no0wall derivative rather than  
> being based on freeNAS?

Yes, the product I pointed to, *as shipped*, runs linux.

You can think of 'm0n0wall' as a specialized FreeBSD "distro" for  
networking hardware.FreeNAS is a 'spin' of m0n0wall focused on  
supporting fileservers, rather than routers/firewalls/Access Points.

For this application, I prefer FreeBSD over Linux.  There are many  
reasons.

For one thing, the ZFS support is further along, and Linux's "FUSE"  
architecture (necessary to adopt ZFS on linux, because ZFS isn't  
(yet?) licensed under a GPL-compatible license, so FUSE is used to  
keep the ZFS code in user-space), is never going to be 'fast'.

For another, FreeBSD's "Geom" architecture, so GELI and GDBE become  
options.   Now if you note that I explained that I'd found a board  
with an on-board HiFn crypto accelerator, (one that just happens to  
already be supported by FreeBSD's "crypt' framework (supported by  
GELI)), you can probably put the pieces together.  :-)   GELI also  
has some interesting 'features' that allow me to market a key  
recovery service.

Putting FreeBSD, ZFS (and a variant of FreeNAS) on the product  
involves some work, its true.

But I think I get a better product out of it than just sticking  
FreeNAS on a PC.

And remember, the hardware I'm buying is identical to that marketed  
by Intel, but I don't pay Intel's "uplift" (nor the channel margin)  
seen in the $560 price.

Jim
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Re: [LUAU] Anyone use a Linksys NSLU2? USB hard disk drives are FOSSfriendly?

[Jim Thompson]

Brian Chee wrote:
My biggest bitch about "normal" machines is that I want my NAS up  
all the

time and a 350watt power supply could potentially add something like
$20/month to my electric bill


As a partial aside - if a power supply is rated at 350 watts, does  
this

mean that it constantly pulls 350 watts?  If so, I may need to do a
costs-benefits analysis of my own pc based file servers.


Simple switched power supplies employ a simple full wave rectifier  
connected to a large energy storing capacitor. Such a power supply  
draws current from the AC line in short pulses when the instantaneous  
line voltage exceeds the voltage across the capacitor. During the  
remaining portion of the AC cycle the capacitor provides energy to  
the power supply.


The problem is that charging or discharging a capacitor may cause  
energy loss even if no dissipative elements are apparent.


Consider two capacitors and a switch:

V=VI   V=0
  --/   --
  |  |
C1= =  C2
  |  |
  

Q=V*C

V=VI/2V=VI/2
   ---
  |  |
C1= =  C2
  |  |
  

E=(C*V^2)/2

The top figure shows a capacitor C1 charged to voltage Vi and no  
voltage on capacitor C2 before switch closure.


C1 is equal to C2 and the energy in the system is:   Energy =  
(C1*VI^2)/2


After switch closure (bottom figure), the charge and voltage is  
divided equally between the two capacitors (conservation of charge)  
and the total energy in the system is: Energy = (C1*(V1/2)^2)/2 + (C2* 
(V2/2)^2)/2 = (C1*V1^2)/4


But wait, half the energy has disappeared. Where did it go?

The energy lost in directly switching voltage to a capacitor at  
another potential is lost in parasitic resistance, and if the  
resistance is too low, in arcing or welding of the switch contacts.   
Potentially some is also lost to radiation.


Resistance. The easiest loss mechanism to show analytically is the  
loss in parasitic resistance, such as the capacitor equivalent series  
resistance (ESR) or wiring resistance. Adding this resistance to the  
circuit and calculating the power dissipated shows the energy loss.  
The energy loss is independent of the value of the resistance.


Arcing. Most switches used in power supplies are solid state and  
arcing is not a problem, but if a capacitor is charged through a  
contact, arcing may be a problem.


Radiation. High rates of change of voltage or current result in  
radiation. Directly switching voltage to a capacitor at another  
potential is a potential source of radiation (EMI).


Note that the losses are the same if C1 is a voltage source instead  
of a capacitor.


Switching supplies also feed harmonics (at the frequency of the  
incoming voltage) back onto the powerlines. The problem arises when  
systems draw current from the energy storage capacitors in the ac-dc  
front-end supply in narrow, high-amplitude pulses.  These harmonics  
can cause real problems for the utility, because they cannot  
compensate for the harmonic current by adding capacitors or  
inductors, as they could for the reactive power drawn by a linear  
load.  (This is more of a concern for large industrial loads, such  
as oh, large water well pumps.  Not that I ever played with those  
for a living.)


These pulses contain harmonics that interfere with other equipment on  
the line and reduce the maximum power that can be drawn. In addition,  
the distorted line voltage causes capacitor overheating, dielectric  
stress, and overvoltages in insulation.


The normal solution here is to put a filter that passes current only  
at the frequency of the voltage (e.g. 50 or 60 Hz). This filter kills  
the harmonic current, which means that the non-linear device now  
looks like a linear load. At this point the power factor can be  
brought to near unity, using capacitors or inductors as required.  
This filter requires large-value high-current inductors, however,  
which are bulky and expensive.


The modern solution is to use an active Power Factor Correction (PFC)  
circuit.  A PFC circuit usually consists of a number of capacitors  
that are switched by means of a contactor. These contactors are  
controlled by a regulator (digital varmetric relay), that measures  
power factor in an electrical network.


About 30% of the world's markets—including Europe, China, Japan, and  
several states in India—have required PFCs (starting in 2001) in  
switching supplies for computing gear. Though PFC hasn't been  
mandated yet in the U.S., the IEEE is at work drafting standards.   
Still, the fact that many power supplies are now sold world-wide  
(such as the power supply for your notebook), means that PFCs are  
present in some computing gear sold in the US.

Put simply?   Modern switched power supplies are more efficient.


On Dec 27, 2006, at 6:34 PM, Brian Chee wr

Re: [LUAU] Anyone use a Linksys NSLU2? USB hard disk drives are FOSSfriendly?

[Brian Chee]

While it doesn't pull a constant 350watts, there is a minimum that is
constant. This is why I'm looking towards something with a much smaller
power supply that is closely matched to the total load.
(drives+interfaces+motherboard+CPU+RAM) This is the reason why most of the
appliances go with either wall warts or inline power supplies. Typically
these types are in the 35watt range.

So for instance the 250gb snap server appliance has a 60watt power supply
pulling 44watts off that under full load. I can afford to keep a 60watt
light bulb burning, but a 400watt like in my old IBM Netfinity server is
more like keeping a small hairdryer running...a bit different.

The Medallion by TechSol that I was using for the PODS project didn't have
a floating point processor (I dont' think NFS or SMB needs it) and can be
run with a 30watt wall wart and depending upon what i/o you turn on, can
drop its load down under 10watts with ethernet+IDE+LCD running. We got the
medallion down to 32mw in deep sleep, and something like 3 watts with most
of the i/o turned off and only jumped up to 3 watts when we turned the
radio on. (VGA, serial, USB, etc all take LOTS of power)

Ideally what I would love to build is a medallion (or Via) based system
running something like freeNAS on a super small power supply to float
charge a 12volt gel cell to avoid the efficiency loss in a UPS. This is
why my home security system takes so little power, same deal. My only
hesitancy is that I may need more CPU horse power than a strongarm 1110
can provide if I want to implement iSCSI.

One thing to note, if you plan on playing with virtualized load balancing
like VMWare ESX server (VMotion) you MUST be using iSCSI at a minimum
since SMB/NFS NAS will NOT work.

/brian chee



University of Hawaii at Manoa
School of Ocean and Earth Sciences and Technology (SOEST)
Advanced Network Computing Laboratory (ANCL)
2525 Correa Road, HIG 500
Honolulu, HI  96822
Voice: 808-956-5797   Email: [EMAIL PROTECTED]
Brian J.S. Chee, CNE/CNI
http://ancl.ics.hawaii.edu

On Wed, 27 Dec 2006, R. Scott Belford wrote:

> Brian Chee wrote:
> > My biggest bitch about "normal" machines is that I want my NAS up all the
> > time and a 350watt power supply could potentially add something like
> > $20/month to my electric bill
>
> As a partial aside - if a power supply is rated at 350 watts, does this
> mean that it constantly pulls 350 watts?  If so, I may need to do a
> costs-benefits analysis of my own pc based file servers.
>
> > /brian chee
>
> --scott
>
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Re: [LUAU] Anyone use a Linksys NSLU2? USB hard disk drives are FOSSfriendly?

[R. Scott Belford]

Brian Chee wrote:

My biggest bitch about "normal" machines is that I want my NAS up all the
time and a 350watt power supply could potentially add something like
$20/month to my electric bill


As a partial aside - if a power supply is rated at 350 watts, does this 
mean that it constantly pulls 350 watts?  If so, I may need to do a 
costs-benefits analysis of my own pc based file servers.



/brian chee


--scott
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Re: [LUAU] Anyone use a Linksys NSLU2? USB hard disk drives are FOSSfriendly?

[Jim Thompson]

On Dec 27, 2006, at 12:22 PM, Brian Chee wrote:

My biggest bitch about "normal" machines is that I want my NAS up  
all the

time and a 350watt power supply could potentially add something like
$20/month to my electric bill

Ideally I'd like to find something in the 120watt or under range  
that can
still support a decent amount of disk (quan 2 SATA drives). So far  
I haven't
found anything, but I leave in a couple weeks for CES in Lost Wages  
and hope
to report on what I find...I'm especially keen on hunting around  
the Taiwan,

China and Korea pavilions for OEM parts.


Yeah, you too.

(Las Vegas is my barrio.)


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RE: [LUAU] Anyone use a Linksys NSLU2? USB hard disk drives are FOSSfriendly?

[Brian Chee]

My biggest bitch about "normal" machines is that I want my NAS up all the
time and a 350watt power supply could potentially add something like
$20/month to my electric bill

Ideally I'd like to find something in the 120watt or under range that can
still support a decent amount of disk (quan 2 SATA drives). So far I haven't
found anything, but I leave in a couple weeks for CES in Lost Wages and hope
to report on what I find...I'm especially keen on hunting around the Taiwan,
China and Korea pavilions for OEM parts.

/brian chee

InfoWorld Media Group c/o
University of Hawaii SOEST (ANCL)
2525 Correa Road, HIG 500
Honolulu, HI 96822
Tel: 808-956-5797, Fax: 877-284-1934

-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of David Kiwerski
Sent: Wednesday, December 27, 2006 7:00 AM
To: LUAU
Subject: Re: [LUAU] Anyone use a Linksys NSLU2? USB hard disk drives are
FOSSfriendly?


Just a thought...

A friend of mine set up his using a regular computer, 2 250Gb ide drives 
and FreeNAS  (free for the download).   Said it took him about 5 minutes 
to set it up.   That was about 6 months ago - he just uses it as if it 
were another drive.   The computer doesn't have to be very fast 
either.   I believe he said he had a Pentium 750, or something along 
that line.

Dave


Jim Thompson wrote:
>
> Intel OEMs a box with a 400MHz 80219 Xscale controller and a SATA 
> controller that will house up to 4 3.5" SATA drives.
> It has 2xGigE + 2x USB 2.0 coming out of it, and .. it runs Linux, and 
> supports CIFS/SMB and NFS out of the box.
>
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