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Very Low Power Home Server And ADSL Modem?


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#1 jsharris

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Posted 03 April 2016 - 07:50 PM

First off, I'll start by saying this is an idealistic project, rather than one that's aimed at being cost-effective in terms of paying for itself by the energy saving. Think of it as an intellectual challenge, one that I'm prepared to spend some time and money on trying to solve.

I'll start by saying giving some background, that may help explain where I'm coming from.

I've been running a home server for years, originally using a early Mini-ITX fanless board, with a small, 60Gb laptop HDD, but recently rebuilt with a cheap, second-hand, D525MW dual core Atom Mini-ITX board, 120Gb SSD and 4Gb of DDR3. It draws about 12W on average, from a 12V power supply (a battery pack) and is dual use, in that it's installed in the new house and is running Linux Mint as a simple desktop, with an old keyboard, mouse and display to give me temporary internet access over there. Before the original 32 bit Mini-ITX motherboard failed (having been on continuously for around 6 years) it was hooked up to two 3.5" 500Gb HDDs, set up as mirror backups (running Linux) and was headless, acting as our home file server, back up etc, but not working as a web server or email server.

I rebuilt this Mini-ITX box with the intention of using it as our new home server, but adding a web server and email server as well. To make this robust, I built a multi-output UPS, that powers the ADSL modem/wireless router, an 8 port switch, a 500Gb USB HDD and the Mini-ITX box (now running 64 bit Mint). The problem is that the power drawn by all this lot is still (relatively) high. The ADSL/wireless modem uses around 6W, and, although I can power it down at night at the moment, I won't be able to when we start using it as a web server, and, more importantly, an email server.

What I'd like to build is a robust, extremely low power, battery powered (with PV daytime charging, as I have now) ADSL modem, home server, web server and email server. I don't need this box to have a wifi capability, as I'm quite happy to lose our wifi connectivity if the mains fails.

An obvious candidate for the server would be a board like the Raspberry Pi, but that's less than ideal, really, as despite its low'ish power, it doesn't have a SATA port, and that rules out using a low power SSD except via a (relatively) high power USB interface, which isn't that sensible. So, I'm looking for ideas for a very low power board, with an Ethernet port and a SATA port, plus a USB port. I don't really need anything else, just enough on-board memory to run a cut down Linux package, plus LAMPS and a handful of email stuff and spam filtering. I'm a bit stumped at coming up with anything that fits the bill.

The really challenging bit seems to be finding a very low power ADSL modem. Such things seem to be like like rocking horse poo, so I'd be really grateful if anyone has any ideas.

I'm quite prepared to sort all the hardware, power supplies etc, and ideally I'd like to build a single box with the ADSL modem, server, power supplies and a lithium battery pack, with just an external charging connector, ethernet port and USB port, plus a phone line connection. I can't see a need for this to have any display, keyboard or mouse ports, as I'm pretty sure it could be completely headless and only be accessed via an Ethernet connection, rather like a router or NAS drive.

Anyone got any ideas as to what's available for such a system?

#2 SteamyTea

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Posted 03 April 2016 - 08:14 PM

Have you looked at some of the latest NASs, I think some can work as a web and email server (my cheapy can run uTorrent on its tod).

I think Damon has done a lot of work on this very low power stuff. He sent me a link once, no idea where it is now.
Something to do with racing to the end and stopping the LEDs lighting up.
May be worth having a hunt around his website.

http://d.hd.org/

#3 jsharris

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Posted 03 April 2016 - 08:31 PM

Thanks, I had already looked at the modders who have managed to hack some of the older NAS units into Linux servers, but (and I could be wrong) these aren't always that low power, and always seem to have fans in them (certainly the Buffalo NAS I have makes a hell of a noise when it's running, both from the fan and the HDD).

Damon was going to be my next port of call, as I know he's played around with some low power plug computers (the sheeva?) and other stuff, which is halfway to where I'd like to get.

I'd love to just be able to buy a very low power ADSL modem board, plus a credit card sized low power board like the Raspberry Pi, add a nice low power SSD (the 120Gb one in my resurrected Mini-ITX box uses less than 1W when writing, and only about a tenth of that when sitting idle, and it's very fast) and build a box that is silent, low power and mains independent.

#4 PeterW

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Posted 03 April 2016 - 08:50 PM

Jeremy - the TP Link stuff has ridiculously low power PSUs - they are normally in the single watts and I know the one I'm running (which seems to be better than the V***in M**ia rubbish) is low powered.

Seems to be the more ports they add, the higher the power.

http://www.tplink.co...el=TD-8817#spec

The 8817 is a 5v 1A unit, would be surprised if it was half of that.

#5 SteamyTea

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Posted 03 April 2016 - 08:51 PM

I have an old ADSL modem that came from my ISP when I moved down here, so over 10 years old.
I shall try and dig it out and see what power difference it makes when I plug it in to the laptop.

This Acer Aspire ES1-512-C5YW uses about 8W when working. I am sure with some tinkering i.e. screen off, SSD and some OS mod/different OS, that could be easily halved.
And it was only 200 quid from Tesco. Bit more from Amazon:
http://www.amazon.co...k/dp/B00OA4YJZO
Would think it would be easy to make a battery pack for it that charges from PV.

Edited by SteamyTea, 03 April 2016 - 08:56 PM.


#6 jsharris

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Posted 03 April 2016 - 09:13 PM

View PostPeterW, on 03 April 2016 - 08:50 PM, said:

Jeremy - the TP Link stuff has ridiculously low power PSUs - they are normally in the single watts and I know the one I'm running (which seems to be better than the V***in M**ia rubbish) is low powered.

Seems to be the more ports they add, the higher the power.

http://www.tplink.co...el=TD-8817#spec

The 8817 is a 5v 1A unit, would be surprised if it was half of that.

Thanks a lot for that. Interestingly I'm using an ancient TP Link (with wifi) over at the new house (just because it was spare) and it doesn't run as hot as the all-singing, all-dancing, Netgear thing I have here, that has loads of things I never use, but does seem to use around 10 to 12 W all the time it's on.

Running on 5V is a distinct advantage, too, as I already have a low power 5V driven 8 port switch, and the switch mode supply in my existing UPS has plenty of spare capacity, so could run this ADSL modem as well.

The idea would be to separate out the wireless router and keep that mains powered, on the existing time switch, but not use the built in ADSL modem (or I may just look around for a low power stand alone wireless modem, with no ADSL modem).

The key thing I want to make as robust as I can is the incoming ADSL line connection and the server. I can accept the wifi going off as long as I can keep the wired network running with a working internet connection.

#7 jsharris

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Posted 03 April 2016 - 09:25 PM

View PostSteamyTea, on 03 April 2016 - 08:51 PM, said:

I have an old ADSL modem that came from my ISP when I moved down here, so over 10 years old.
I shall try and dig it out and see what power difference it makes when I plug it in to the laptop.

This Acer Aspire ES1-512-C5YW uses about 8W when working. I am sure with some tinkering i.e. screen off, SSD and some OS mod/different OS, that could be easily halved.
And it was only 200 quid from Tesco. Bit more from Amazon:
http://www.amazon.co...k/dp/B00OA4YJZO
Would think it would be easy to make a battery pack for it that charges from PV.

I've been surprised at the difference in power consumption I gained when swapping out the old Mini-ITX board for the Intel D525MW board, plus changing the old 19V power supply for a tiny (as in built in to an ATX power connector) 12 V power supply. Together with swapping out the old 60Gb 2.5" HDD and fitting the low power 120 Gb SSD I've probably increased the computing power of this little box by a factor of ten and more than halved its power consumption. It rarely draws more than an amp from the 12V supply, and I'm currently running it from a 100 Ah 12V battery, via a couple of switch mode regulators. The Mini-ITX box is running from a high efficiency buck-boost 12V regulator, so even if the battery drops below 12V, 12V is maintained to the box. The 12V supply is also running the old TP Link wireless ADSL modem/router and a 5V regulator is running the 8 port switch plus a USB port that I use to run additional USB HDD storage (set so the USB ports power down when idle, as the USB HDDs are just for long term storage and back up, the constantly running stuff uses just the SSD).

What I really like is having a few small boxes that use very little power and are totally silent.

#8 gravelld

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Posted 03 April 2016 - 11:09 PM

Do you need a lot of storage? Why not just use an SD card with an rPi?

Used to use IDE compact flash on my Mini ITX builds. Those were the days.

#9 TerryE

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Posted 03 April 2016 - 11:21 PM

Jeremy, just out of interest why do you want SSD? In my experience with Linux if you are running a single user PC or server then if you've got enough RAM then a laptop SATA or eSATA 2.5" HDD, say 0.5 Tb is plenty fast enough for anything that you want to do.

#10 DamonHD

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Posted 04 April 2016 - 12:32 AM

JSH: my entire server (including mail server, primary DNS, static and Java web servers) runs on an RPi with storage on the SD card, from off-grid PV:

http://www.earth.org...y-Pi-setup.html

Due for an upgrade for a newer model sometime soon.

Basically draws a couple of watts, and is of course fanless and silent.

When there's enough energy available the Internet connection (router + FTTC) is pulled off-grid too (another ~10W):

http://www.earth.org...grid-stats.html

Due for an upgrade on the battery wiring soon also, since I seem to have ~0.25R impedance between battery and load at the moment, and I'm sure that I could do better, getting tighter control and the ability to run larger loads.

Rgds

Damon

Edited by DamonHD, 04 April 2016 - 12:35 AM.


#11 jsharris

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Posted 04 April 2016 - 07:00 AM

View Postgravelld, on 03 April 2016 - 11:09 PM, said:

Do you need a lot of storage? Why not just use an SD card with an rPi?

Used to use IDE compact flash on my Mini ITX builds. Those were the days.

This server currently acts as the house backup file server and the secondary repository for all our music, photos etc. I need around 300 Gb of storage, and currently run two 500Gb drives in RAID 1 in a separate box, that is only powered up for daily backups or when it gets an access request.

#12 jsharris

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Posted 04 April 2016 - 07:08 AM

View PostTerryE, on 03 April 2016 - 11:21 PM, said:

Jeremy, just out of interest why do you want SSD? In my experience with Linux if you are running a single user PC or server then if you've got enough RAM then a laptop SATA or eSATA 2.5" HDD, say 0.5 Tb is plenty fast enough for anything that you want to do.

The 120Gb SSD just significantly reduces the power, mainly because of its very low idle power compared to a 2.5" disc. It's also silent, which in a fanless box does mean that there is no noise at all. 120Gb is enough for 99% of things I'm working on, if there's a request for data not on the SSD then it fires up the RAID box and pulls it from the disks in that, but that is a pretty rare event, as we don't stream music from the server, but have it locally stored for use (as in on a USB stick plugged into the car or on the USB stick that's plugged into the audio system at home). Every evening at 6pm my main PC fires up and synchronises the user files with those on the RAID array, as a backup. I have a separate NAS box that holds a full system backup on the main PC but that only gets used after I've made any changes to the system (like installed some new software), as it takes hours to do a system backup (overnight usually).

#13 jsharris

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Posted 04 April 2016 - 07:10 AM

View PostDamonHD, on 04 April 2016 - 12:32 AM, said:

JSH: my entire server (including mail server, primary DNS, static and Java web servers) runs on an RPi with storage on the SD card, from off-grid PV:

http://www.earth.org...y-Pi-setup.html

Due for an upgrade for a newer model sometime soon.

Basically draws a couple of watts, and is of course fanless and silent.

When there's enough energy available the Internet connection (router + FTTC) is pulled off-grid too (another ~10W):

http://www.earth.org...grid-stats.html

Due for an upgrade on the battery wiring soon also, since I seem to have ~0.25R impedance between battery and load at the moment, and I'm sure that I could do better, getting tighter control and the ability to run larger loads.

Rgds

Damon

Thanks Damon, I had a feeling you'd already done pretty much what I'd like to do.

I shall take a look at your system and see if I can do something similar.

#14 SteamyTea

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Posted 04 April 2016 - 08:42 AM

Couple of watts usage from the old BT ADSL modem


#15 jsharris

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Posted 04 April 2016 - 09:01 AM

That's very good, compared to the all-singing, all-dancing Netgear unit I have at home. That uses around 12W, but has lots of functionality that I don't really need (like a USB disc drive port, to use it as NAS, 5 Ethernet ports and some fancy stuff that's intended to make it easy to set up). It runs uncomfortably warm to the touch, too.

I've ordered one of those low power TP Link ADSL modems, so will have a look at how much power it draws when run from a 5V supply. I suspect it may well be around the same as that BT one you've measured.

Edited by jsharris, 04 April 2016 - 09:03 AM.


#16 DamonHD

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Posted 04 April 2016 - 09:37 AM

Note JSH that I run everything at 12V nominal since (a) that's what my battery bank is and (B) the router and FTTC equipment is rated for 12V in, thus avoiding any conversions there at all for me. Router is ~2W with energy-saving features engaged, FTTC ~8W.

I have a switching version of a 7805 to get me down from 12V nominal (really 11.5V to 16V) to 5V for the RPi and a few USB peripherals.

(I actually have wired-OR combination of a small LiFePO4 pack with the main LA bank to power the RPi via the 7805-alike: http://www.earth.org...rid-system.html )

Rgds

Damon

#17 jsharris

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Posted 04 April 2016 - 09:41 AM

Following on from the observation made here: http://www.ebuild.co...er/#entry165552 I'm inclined to look at just optimising the Mini-ITX system I have, by using a lower power ADSL modem (the TP Link one mentioned above) and running the ADSL modem, Mini-ITX box with it's dual core Atom and the 8 port switch from the battery supply. All told that little lot is only going to draw maybe 15W, and I can easily deliver that from the battery 10 to 12 hours every day, as it's only around 12 to 15% discharge each night.

Currently the system is set up so that a time switch turns on a mains charger at 9 am, in the hope that the PV panels are producing enough to cover the battery re-charge, but in future I could very easily add smart charging, as I broadcast the "excess power - turn load on" signal on an 868MHz wireless link. At the moment it's only the Sunamp PV that receives this signal and turns the load on, but it would be dead easy to add another receiver coupled to a smart switch that could detect state of charge and decide whether to use excess PV charging, grid charging or no charging at all.

Damon, my system also runs at 12V at the moment. I built a box with some high efficiency switched mode supplies, including a 12 V buck/boost one that will deliver 12V out over an input range of 7V in to 24V in to run the Mini-ITX box, and a 5V supply for the network switch (which has spare capacity to run the 5V modem). This box also has a 100W charger for the 100Ah ex-server UPS sealed lead acid battery.

Edited by jsharris, 04 April 2016 - 09:45 AM.
crossed with Damon


#18 SteamyTea

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Posted 04 April 2016 - 09:51 AM

Is the biggest problem with the PSUs. Could we save more energy by just getting better ones.
I have a mixture of things 'hanging around the phone line'. Maybe I should have a look at all the voltages and usages (again as I did all this over at the 'other place'), then get a decent power supply.

And why can't we use the power in the phone line? Probably illegal.

Edited by SteamyTea, 04 April 2016 - 09:52 AM.


#19 jsharris

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Posted 04 April 2016 - 09:57 AM

There are losses in power supplies, and generally it makes more sense to use a single high efficiency switched mode supply to run several devices that run on the same DC voltage than it does to have individual supplies for each. You can buy high efficiency DC-DC converters, that use synchronous rectification rather than diodes, that are around 95% efficient. Used with a battery with a good round-trip efficiency (mine isn't that good) you can get both reduced power consumption overall and the advantage of having interruptible power, at least for a day or so, in the event of a power cut.

Edited by jsharris, 04 April 2016 - 09:58 AM.


#20 gravelld

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Posted 04 April 2016 - 10:44 AM

I think you're making a good choice sticking with Mini-ITX. I always liked the boards produced in that factor, especially by VIA. Install the OS on an SD card, just spin the backup disks up when required.

Not sure if it's of interest but the audiophile community are into powering via DC from batteries these days. Might be some nuggets on Computer Audiophile.