Cacti on PI


sudo apt-get install dirmngr

sudo apt-key list

ubuntu’s key servers – you should verify these yourself…..

sudo apt-key adv –keyserver –recv-keys E0B11894F66AEC98

sudo apt-key adv –keyserver –recv-keys 7638D0442B90D010

sudo apt-key adv –keyserver –recv-keys 8B48AD6246925553

Debians Key servers

apt-key adv –keyserver –recv-keys 0x1827364554637281

backports repo

sudo nano /etc/apt/sources.list

deb stretch-backports main (contrib nonfree)

sudo apt-get update  

now install – need to tell it what to install….. and from where

sudo apt-get install -t stretch-backports cacti

Mining Electroneum

So today a coin is worth around 15p and electricity is 14p/kw/hr.

So first of all lets deal with the money side. I’m generating 900H/s using 365j/s (w) of energy. Scaling this upto a day’s hashing, thats 77MH/day and earns around 26ETN/day. It uses 8.76Kw/day which is £1.22/day. So the ETN is worth £3.90 and it costs £1.22 to generate. That’s a profit of £2.68 per day. Winner winner, chicken dinner.

So the hardware I’m using…. 2 old desktops and 2 old laptops.

PC 1 – Intel Core2 Quad Q9300 maybe? (has VM’s running on it which are more important than mining). Has a 750Ti installed. No AES NI support on proc.
PC 2 – Intel Core2 Duo (doesn’t do anything other than host a GPU (with the CPU mining also). Has a 750Ti installed. No AES NI support on proc.
Laptop 1 – Intel quad core? Has AES NI support.
Laptop 2 – Intel quad core? Has AES NI support.

Given that this was all old hardware, i’m not seeing any negative impacts of running this, and the extra heat is useful this time of year I think it’s a thumbs up for now.


So I’ve been working for a few weeks on this idea, and now I kinda have a working prototype. The idea is for a web based copy of something like the Gnome System Sonitor utility found in many Linux distro’s. I need it web based so I can install and monitor web server I don’t have root access (shared hosting platforms) while some rather intense scripts run. Here’s a quick clipping of my very prototype, prototype. Black is actual and red is 3 sample moving average. I admit it looks nothing like the Gnome System Monitor, but it’s a step towards what I want to achieve.



Things that I need to do next;

  • Change the PHP backend to a JSON responder, (think like AJAX)
  • Improve the p5.js front end to actually look and feel more like Gnome System Monitor.

My prototype code is available here;

Design note: want it to be JSON so that a user can mod the front end to monitor more than one system, and it seems sensible.

How to install x11vnc vnc server on ubuntu 17.04, for remote access or screen sharing

Here’s some commands (see video for more instructions);

sudo nano /lib/systemd/system/x11vnc.service 

Description=x11vnc service

ExecStart=/usr/bin/x11vnc (your switches)
ExecStop=/usr/bin/killall x11vnc


systemctl daemon-reload
systemctl enable x11vnc
systemctl start x11vnc

and if you want to see if it’s working ok try

systemctl status x11vnc failing :/

So recently I’ve noticed that the site is struggling quite badly to process the data – the database has grown to just shy of 2.5GB and well it’s not optimised is any way at all.

So there’s 95173 teams from my last data collection and of those 2158 have a score of 0 and 164 have no WU. IE these are unused teams. So in total over the last 5 months, that’s generated an extra ~300k of history records that are not needed at all. Then there are the teams who are not active, also having many records that I don’t really need to worry about creating.

To put things into context – this is a pruning exercise. The DB is too big, so the useless data needs to go. Given that in the 5 months my team has risen to the top 3000 teams with less than 2 machines running for that time, I don’t think this will affect the data validity or usefulness of the site long term.

So to keep the ship from sinking I think it’s time we removed the teams with no WU or Score from the history (after creating a backup). When I say no WU or score I actually mean all teams with less than 10 WU and less than 200 score.

So “SELECT * FROM `teamhistory` where score < 200″ yields 974,625 records and “SELECT * FROM `teamhistory` where wu < 10″ yields 4,459,439 records. Given there’s around 14,000,000 records, removing 30% of them should see a massive speed up in future queries. 

So after deleting some records, the table seems to have shrunk, but I think I will have to review how I keep team history in the future and the size of the fields in the table as it has grown way too fast from January till now.



So this week I’ve been working on two LED projects, one of them is more just a thing I want to do for some pub gigs and that and the other might develop into a sellable product.

So number 1: 

Recycling some old tape into LED panels for lighting bands and stuff at pub gigs, in my workshop for making videos and maybe on gigs ect. It’s a somewhat limited design but, small panels with upcycled LED tape stuck to them, controlled by some LED drivers that I’ve had lying about for some time now doing nothing. After an hour of fiddling, I proved the concept for my needs and I will now order some connectors to make 6 panels for further experimenting.

prototype LED panel

prototype LED panel

and number 2:

So it’s a 5 by 5 PixelPanel, using some recycled ws2801+5050 LED’s, and my idea is to make these panels controlled by Artnet and use PoE to power them. Still very prototype at the moment! Sorry for the crap photo.

5 by 5 LED PixelPanel

5 by 5 LED PixelPanel

Todays trip to the IoT expo 2017 was disappointing.

So I turn up – hop in a lift upto the 2nd floor – the lift has a CAN bus error, still working tho :s. Then I proceed to get my badge, the printer has a jam, and the next kiosk just refuses my barcode…. off to see a real person it is then. so far the things are letting down the team.

So I have a little wonder round, most cubicles are bland and blank, a few were empty, but had signs up for exhibitors who I guess just show up. I was looking for something new, different or simply cleaver, but I don’t really think I saw anything. I was really surprised not to see Arduino there, or the Raspberry PI Foundation, or AWS…. but Ubuntu was which is ok I guess. Anyway it really did feel fragmented and nothing really flowed.

Here’s the things I found interesting enough to snap.

sponsor banner

sponsor banner

A robotic art, controlled by audio not the internet

A robotic art, controlled by audio not the internet

a Raspberry PI based controller

a Raspberry PI based controller

a weird head thing

a weird head thing

Pub en-route

Pub en-route

Installing Transmission BitTorrent web interface on Ubuntu

Here’s how to do it – if you have the desktop version, most of the hard work has been done for you, but here’s how to open the web interface up to the world/your LAN anyway.

I’ve made a new directory in the root of the drive for files, called transmission.

  1. sudo apt-get install transmission-cli transmission-daemon
  2. cd /
  3. sudo mkdir transmission
  4. sudo chgrp -R debian-transmission /transmission 
  5. sudo chmod -R 775 /transmission
  6. sudo service transmission-daemon restart
  7. sudo nano /etc/transmission-daemon/settings.json
  8. make edits to file:
    1. “download-dir”: “/transmission”,
    2. “rpc-password”: “your-password”,
    3. “rpc-port”: abcd
    4. “rpc-whitelist”: “,192.168.*.*”,
      the password will be hashed on the next restart.
  9. sudo service transmission-daemon reload
  10. sudo service transmission-daemon restart
  11. enjoy vie web interface. 😀
  12. remember to push a port through your firewall….

If you want to do this from the server distro, you’ll need to install ‘transmission-common’ also.

Up-cycling an old server? pt 2

So today I decided it was worth adding in the second GTX 750Ti that was donated to me. this was successful and I managed off a 500w PSU to have the dual core CPU and the 2 graphics cards folding. The cpu has a 65w TDP, and the graphics cards are supposed to be 75w ish each, which means 215w plus the HD all off the 12v rail. Well the PSU is 17A 12v which is a maximum of 204w…. hummmmm. But worked fine.

I did some measurements as I added bits in;

  • 0w unpluged (well durr),
  • 5w standby power consumption,
  • 69w powered on but idling (one GPU installed),
  • 139w with 1 CPU and 1 GPU folding at max,
  • 151w with 2 CPU and 1 GPU folding at max,
  • 81w powered on but idiling (two GPU installed),
  • 152w with 1 CPU and 1 GPU folding at max (2nd GPU installed and idiling),
  • 172w with 2 CPU and 2 GPU folding at max.

So, comparing this for folding to my post here, (based on 24hr period):
the M600 server blade 23000/8.64kWh = 2662 points/kWh,
the QC Core 2 Quad 6500/2.62kWh = 2480 points/kWh,
the QC with 750Ti 38000/3.6kWh = 10500 points/kWh,
the DC with 2 750Ti 76000/4.13kWh = 18402 points/kWh,

Meaning that the dual GPU setup is clearly the winner…

QC with the 750 would generate around 13,870,000 points/year and cost £130 a year to run, the DC with 2 750 would generate around 27,740,000 point/year and cost £150 a year to run… clearly the new setup wins… but… NO.

The problem here is that I want to use the host to run some VM’s doing specific tasks, but with each GPU tying up a CPU core, and only being a dual core machine this would be a hopeless setup. Not to worry – I have a few Quad core machines lying about not doing anything so, I pop in a Core 2 Quad and well… it didn’t work! back to the manuals. So this clearly shows that it does support Core 2 Quad’s, but not the quad core’s I have which are the Q9300. See comparison here between the DC and QC I have and the one I should install. Damn it.

I should really think about the 12v supply a bit more – moving buying and installing a Q6600. It would potentially push me way past the PSU supply limit (75+75+105= 255w, 204w limit). This is one reason why anyone using multiple graphics cards is installing massive PSU’s not for the Wattage, but need for a massive 12v supply rail.

Ah well – time to commit to the dual core with only 4GB RAM for the time being. 🙁

Forgot to mention i found this old diagram for the original motherboard

Original mobo

Original mobo