Howto: Ethereum/Expanse Mining with Ubuntu 16.04.3 LTS

First of all – install Ubuntu [1]. This should be actually straight forward. After running the installation I suggest to do a software update. Just drop the more or less “standard” lines:

sudo apt-get updatesudo apt-get upgrade

To be able to mine, I suggest to check the video card drivers. In my case for the Nvida GTX 780 I use the nvidia-384 proprietary drivers. The following guide might be useful [2] for the installation – either via graphical user interface or via command line.

Now let us install the ethminer. Fast and easy with the following commands as pointed out at [3]:

sudo apt-get install software-properties-common
sudo add-apt-repository ppa:ethereum/ethereum
sudo apt-get update
sudo apt-get install ethereum ethminer

And for the first test I run it on an Expanse Pool [4]:

ethminer -F -G

Starting it the first time, it takes some time to load the DAG, but once it’s loaded the miner performs better as expected showing a Hash Rate of approximately 17 MH/s – on the miner and on the pool.

For an autostart of the ethminer process, I will drop another blog entry within the next days/weeks.

[1] Ubuntu, Download Page

[2] Ubuntu Help, Nvidia Binary Driver Howto

[3], Ethereum GPU mining on Linux

[4], Expanse Mining Pool

Optimizing geth client for Ethereum

Running the geth client [1] in default mode, requires after some time, quite a big amount of disc space. To optimize it, the fast syncmode can be enabled. What is does is basically syncing only the latest part of the blockckain instead of the whole chain.

So after running the Ethereum Pool on [2] for some time, I noticed that the disc space was going down rapidly. To fix it, I decided to go for the fast-sync mode with some optimization.

It should be highlighted that for running geth in fast syncmode, the whole database has to be deleted and rebuild. Therefore, since the geth client on [2] runs as main and backup on two servers, I first migrated the backup server.

To do so, the first step is to clean out the database by running:

geth removedb

After cleaning out the database, we can restart the geth client, with syncmode fast. Additionally I added the cache option, to increase the cache of geth from the default 16MB to 1GB. This should give the client an extra boost.

geth --syncmode=fast --cache=1024

To check the status of the syncing, you can log-in to geht with

geth attach

and run the command


If the system shows you “false” then your syncing is complete.

After completing the backup node, I shut down the main geth node. So far so good, basically I saw that connected to the backup geth client and continued without interruption.

So now I starting doing the same thing on the main node. And that’s the point where the sh*t hits the fan! After starting the syncing on fast mode on the main node, the mining process switched again from the backup to the main node. This resulted into a desaster, as miners then immediatley found 2 orphan blocks.

To fix it, I reconfigured the pool operating only with one geth node and restarted the processes. Furthermore I deleted the orphan blocks for the database. Neither the less the mining shares of the miners are gone with the old block. That’s definitly something to blame on me.

[1] geth, command line interface for Ethereum

[2], Ethereum Pool


DDOS protection

Did you ever wondered what cloudflare [1] is? It is basically an protection against Distributed Denial of Service attack [2], where your server is attacked via a massive flood of incoming traffic, trying to overload your server.

But there is an easy and cost saving way to protect your server – of course if you are running it on Linux. Simply check DDoS Deflate from github [3]. After installing, the script checks frequently your incoming traffic. Once an IP address generates a critial mass of incoming traffic attempts, the IP address is blocked.

Just consider that you might want to whitelist certain IP addresses or domains – for that check the manual.

Update 2017/12/12:

After installing DDoS Deflate [3] on, the impact can be seen on the statistics of the website. No more peak pointing out a DoS attack since beginning of December.




[2] Wikipedia, Denial of Service Attack

[3] Github, DDoS Deflate


Cryptocurrencies – Gamblers and Game Changers

There is currently a big hype around cryptocurrencies and a kind of battle between Bitcoin and all the Altcoins (alternative Coins). Bitcoin seems to have the first-mover advantage, as techologically, it is lacking behind a majority of other coins.

Bitcoin created a brand and this is rewarded with an explosive up-drift in their exchange rate. Based on Coinmarketcap [1] Bitcoin holds more that 50% of the cryptocurrency market, while more than 1000 alternative coins shares the rest. Still to be mentioned should be Ethereum and Bitcoin Cash. But within this article I will not go into details of their technology and the differences between them.

Having that said, you soon realize that certain cryptocurrencies are

  • the perfect wonderland for gamblers,
  • while others have the power to be a game changer.

For gamblers, for which I see the majority of the cryptocurrencies, the advantages are:

  • the market is never closed, you can buy/sell 24 hours, 7days a week
  • the volatility is rather high – changes of more than 20% a day are not unusual
  • there are plenty of market platforms with low rates
  • More than 1000 cryptocurrencies according to Coinmarketcap [1]
  • as there is no authority, platforms are located offshore, most people don’t pay taxes for their cryptotrading profits

While many of the cryptocurrencies seems to be created either for fun, for world domination – where the most fails, the minority are seeking for real-world applications and having a real vision behind.

Starting with my – just for fun – mining pool project [2] to set up mining pools with 0% fee, I came across Expanse [3]. Operating a pool for Expanse [4] I soon got into the community and the activities behind this project. And to be honest, Expanse is a project I would consider as a possible game-changer.

Beside the fact that Expanse is very community driven there is direct contact to the core team via a Discord Expanse channel [5] which makes the project quite family like. Aside to the chat, there is a bi-monthly newsletter [6] and a Twitter channel [7] keeping the community up to date.

Coming back to the real-world applications and visions, I would like to highlight some of the Expanse core ideas and applications that convinced me:

  • Tokenlab [8]: Its basically an integrated system to create tokens on the Expanse Blockchain. The platform helps to create ICOs with smart contracts, with time-locked distributions to protect investors from funds being dumped.
  • Votelock: a core idea for the integration of voting within a blockchain. This would be a real benificary for elections having a proper infrastructure and security mechanism.
  • [9]: not yet life, but I checked the whitepaper [10] and it looks promising to me. Putting experience and achievements in a blockchain sounds like an interesting idea, kind of a mixture of facebook with LinkedIn in a 2.0 version.
  • Charity: and the people behind are into charity, making them human and caring about others. This gives them an extra point from my side.

Please note that those are just the highlights from my side, I think there are plenty of more features and applications.

Summing it up, I am curious and forward looking for the Expanse project.



[3] Expanse Homepage


[5] Discord, Expanse Channel

[6] Expanse Newsletter

[7] Expanse on Twitter

[8] Homepage


[10] whitepaper


Ethereum, Ethereum Classic & Expanse: Basics about Mining and Mining Pools

In advance, I would like to highlight, that this article will focus on the mining of the following 3 Ethash (previously known as Dagger-Hashimoto) algorithm based  cryptocurrencies:

Basics about Mining

Basically each minable cryptocurrency can be mined solo (stand-alone), with GPU and/or CPU power. CPU mining is not to be considered efficient anymore – therefore most of the mining is done with modern graphic cards (GPU power). Dependent on the difficulty, the algorithm, and the GPU power, it takes certain time to get a reward for finding a new block within the blockchain.

The rewards for finding a new block is different based upon the cryptocurrency:

  • Ethereum (also known as ETH), 5 ETH
  • Ethereum Classic (also known as ETC), 5 ETC
  • Expanse (also known as EXP), 8 EXP

Each of the above noted cryptocurrency uses a certain difficulty required for the mining process. The difficulty is adopted frequently in relation with the network hash rate to the according block time. The block time provides the average time between finding new blocks. For Ethereum and Ethereum Classic the targeted blocktime is currently 15seconds, while for Expanse the block time is targeted with 60sec. Therefore, the more miners provide hashing power, the higher the network difficulty is set. This results that with higher network hash rate and a higher difficulty, the time until the first reward on solo mining is earned later.

Taking for example Ethereum, and a recent graphic card with a hashing power of 30MH/s, would currently take around 3,5 years to earn a reward of 5 Ether – statistically of course. To get an actual view of your mining power check out one of the mining profitability calculators [1].

To overcome this and to be rewarded earlier, you can join a mining pool. Depending on the distribution algorithm, you will be rewarded earlier – while of course, with lower rewards.

Choosing the mining pool

First of all you should get clear on what you would like to mine. Of course you can select the cryptocurrency based upon the best profitability  [1], but I would suggest to also investigate on the roadmap and on the projects of the cryptocurrency & their communities. At this point I would specially like to highlight Expanse as there are some interesting points in their roadmap, interesting projects (e.g. Tokenlab ) as well as a great supportive community.

What are the important points on selecting a mining pool:

  • The reward distribution algorithm
  • The fee
  • The minimum payout

The mining pool reward distribution algorithm defines how rewards are distributed among the miners. The most common ones are:

  • PPLNS – Pay Per Last N Shares: Reward is split based upon the proportion of shares on the last N shares.
  • Proportional: The reward is split proportional based upon all shares required to find the new block.

Of course there are far more algorithm available, which can be found under [2].

The fee is defined by the pool operator. Before splitting the reward across the miners, the fee is deducted from the reward. The fee usually varies between 0% and 2%.

The last variable to consider is basically the minimum payout. Once you start mining, rewards are accounted based upon the distribution algorithm. As transactions costs something, a minimum payout is set. The lower the value, the more often the rewards are payed.

Aside to the hard facts, certain other criteria’s should also be taken into account.

  • Security: Does the environment look safe? Has there been any issues before?
  • User Interface: Is the user interface handy? Do I get all information I would like to see?
  • Additional features: Does the pool provide any additional feature?

My personal favorite

Considering all the above mentioned hard- and soft facts I consider the following pools from the same provider, whereby I have to say that I focused on mining Expanse:

All of them have 0% mining fees and rather low minimum payout values.

The operator is very supportive in case of questions. Furthermore the underlying open source pool software [3] has been extended with new features over the time, whereby I love especially the twitter notification service [4], where messages are posted once a new block is found by the pool. Additional features to be noted there:

  • 24h pool hash rate
  • Support for iPhone Mining Pool Monitor App: Asi MPM [5]
  • Integration of Crypto Currency Market value

The pool process – from mining to payment

What I missed on my research was basically a short description of the process on the mining pool itself.

  • First of all you need to download a wallet and create an account – alternativley you can create an account online
  • Following the instruction of the pool you download a miner like etherminer or claymore, set the ports and your wallet address and then you start mining
  • Once a new block is found and shown under “New blocks” (e.g. on EXP.ethertrench), the overall mining process, with the count of shares starts from the beginning
  • After a certain time, the new block is set as “immature” (e.g. on EXP.ethertrench), for the miners the “immature balance” is calculated and assigned (done by the so called unlocker process).
  • Over the time more blocks are processed and after a certain time, the block is considered to be matured – shown finally under “Block” (e.g. EXP.ethertrench)
  • The payment processed is started once the block is matured. Usually the payment process runs on a predefined frequency – e.g. on an hourly basis.

I hope this article provides some information about the basics, about mining and about choosing the right pool.

Happy Mining!






Private Pilot Licence – Navigation

Okay, navigation is one of the most difficult parts during the training – theoretically and practically. On the theoretical part you might struggle with abbreviations like QDM, QTE and QUJ. On the other side, in one of the first practical lessons I have learned that from top, everything looks similar (at least in the beginning). You might think it is anyway VFR (Visual Flight Rules) and not IFR (Instrument Flight Rules), where it is obvious that you need navigation. No! Once you plan to go to an aerodrome which is not your home base you want to know how to go there – and usually also how to go back to your home base.

So to overcome the feeling of being lost, you usually have several devices in the plane, helping you to navigate:

  • Magnetic Compass
  • Gyroscopic Compass
  • NDB
  • VOR
  • GPS

So you might wonder why you have so many devices. Thinking about a car your GPS might be sufficient enough. So first of all – if you might have an older airplane, you might not have GPS (Global Position System) at all. And once you have it, it can fault, like many high-tech equipment. Furthermore, in case of a solar storm, you might receive incorrect or wrong values. Beside this I have noticed already that in most airplanes the GPS tracking is lagging behind. Focusing on the approach of a GPS mark, once you reach the point – you are usually already 1-2 min over your target. This is important to realize especially in the beginning of your flight lessons. As an aerodrome is not that easy to spot, you should consider by approaching via GPS, the airfield is closer that it might look like.

A VOR (Very High Frequency Omnidirectional Radio Range) is a navigation system based upon radio frequencies. You basically tune in a frequency of a VOR and then select a radial (from/to) the station. In comparison, a NDB is much simpler, as it acts a bit like a compass. It always shows you the direction to the NDB. A more detailed describtion would be far too much for this blog entry. At [1] you will find a good explanation of VOR navigation.  At [2] you can simulate the VOR navigation

What you definitely need is a physical (paper) map. It is a good and cheap backup and helps you especially in the route planning. In combination with a navigation circle, it helps you a lot to get along with the planning. A tip for the route planning is to highlight certain landmarks. E.g. if you have a known castle, sea or highway on the way – it can help you to find your position and routing.

All this stuff you learn already in the theoretical part plus a lot about planning. What was kind of difficult to me was the learning of the different abbreviations, meaning different directions/courses related to VOR/NDB.

  • QDM – ‘Direction Magnetic’ (I prefer ‘Quick, Direct Me!’)
  • QDR – ‘Direction Radial’ (Radial from the station.)
  • QTE – ‘True Emanation’ (true bearing that emanates from the station.)
  • QUJ – God only knows, but it’s the opposite of QTE!

At [3] the relations are quite good explained in German (but should be also clear for English speakers).

At a later stage I recommend the usage of a flight planning software. My preferred solution is SkyDemon [4]. It offers a planning software which can installed on a Windows PC for flight route preparation, storing it and then using it in-flight with a mobile device. Having the proper hardware it even shows you your actual position, speed and course. Also useful is the possibility to show weather information as well as NOTAMs. As the software is actively managed, constantly new features are introduced. Furthermore you have the possibility to store the flight. Another feature I really like is that it can be used also with an flight simulator like X-Plane [5]!


[1], VOR Navigation

[2], Aviation Training Tools

[3], Kursdiagramm

[4] SkyDemon, Flight Planing Software

[5] X-Plane Flight Simulator

Windows 10 and SSD ending up in disk error

To speed up my PC, I decided to buy & install a SSD hard disc. As I have a Windows 10 with plenty of applications and data running I thought about a migration via a disc clone.

Therefore, I first cleaned up my “old” hard disc. I de-installed software I haven’t used for years and removed data, which I have stored already on my personal server or saved within a backup somewhere.

For the next step, I opened the computer management and switched to the storage management. There I reduced the volume size of the actual hard drive. It should be basically less than the capacity of the new drive.

The next step was to clone my disc to the new SSD. There are plenty of tools available in the internet, which can do this. The only thing you really need is: time. Cloning takes some time as the blocks are moved 1:1 from one disc to another.

After letting the clone process run over night, I shut down my PC and de-plugged the old drive. Connecting the new SSD on restarted with the new disk I expected a superfast boot.

But unfortunately: DISK ERROR!

So back and forth, same procedure again didn’t fix anything. After spending several hours, I decided for clean installation of Windows 10. In the end of the installation follows a reboot and again: DISK ERROR!

Sometimes the solution might be so easy. The issue was already on the BIOS side. If you install a SSD you must ensure to switch the SATA controller from Native IDE to AHCI. So, check you BIOS and switch from:




Once this was done, I did one more installation of Windows 10 – and finally it booted.


Outsourcing – the holy hand-grenade of Antioch

Outsourcing – the holy handgrenade of Antioch [1]! As shown in Monty Python and the holy grail [2], that is how certain managers see outsourcing as the solution for cost savings.

Short term

Starting an outsourcing project requires in a first step to document everything. This requires a kind of feedback-circle, and cannot be done within weeks. Once you document something, this doesn’t mean that it is understood by the counterparty. Questions will come up, while the documents need to be continuously improved – which costs time and money.

In addition you will have to set up an paralell organization. There will be the need for a local manager as well as for a retained organisation which is managing it.

Once the word “Outsourcing” is out, people will start looking for new jobs. In the best case (e.g. in big corporates) this will be within the company – but most of them will search for a new company, due to the missing trust. While a certain amount of people will stay till the end, usually the good & qualified people will leave first.

Those aspects in combination will raise the costs in the beginning.

Mid term

Many companies already realized that outsourcing services to “far-away” countries comes with bigger problems. To name a few: cultural clash, organizational overhead, time-zone issues.

So what they do is – they start nearshoring. Another nice word, which should be used for Bullshit Bingo [3]. In Europe that is usually Eastern-European countries, which are not that far away, while still having much lower wages.

The idea is good, but obviously it has not been thought to the end. Imagine you are a young student coming from Bratislava. You start working for an Austrian or German company, with a subsidiary in Slovakia. Your skillset is medium and your salary is low. Once you are gaining experience and expertise, you would like to earn more. You will realize that staying where you are will not increase your salary that much. Therefore you might consider going into nearshore countries, offering a higher income. Higher income attracts more people, while on the mid-term there will be a shortage of skilled, cheap staff.

Even you might consider travel time. I know from colleagues, which are living in Vienna and taking 1h to go by public transport to work. Other colleages are coming from Bratislava, 1h train ride.

Long term

Here I would like to quote Benjamin Franklin: “The bitterness of poor quality remains long after the sweetness of low price is forgotten”. Usually once organizational structures are changed through outsourcing and the transition period is over, you are left with a minority of the former knowledge keepers. The systems and the support might run, cheaper and with less quality. But on the other side, your innovation force will be less. As innovation force I see the combination of idea-bringers, those who are able to bring it to live in a short period and those who will be able to fix it in operations, once it is there. If you have to define an service agreement for each and every task and a specify everything into detail, you might be the last one – in comparison to your competitors – to bring innovation on the market. And for fast-moving businesses the loss of such a first-mover advantage can be very costly. And once this is noticed the management who decided for it, is long gone.

So if you are ever in the position of making a decision on outsourcing try to compare the cost savings with the decrease of income. The cost/income ratio, which is in favor or many investors, has the second component under the divisor – which is often forgotten: income. And income should be driven by innovation!

[1], Monty Python – The holy handgranade

[2], Monty Python and the holy grail


Information about Flight Accidents

As a pilot your are always trying to improve your skills. Therefore it is always good to get reports on flight accidents, causes and possible failures. I actually like the Aviation Herald [1] quite much since it provides always the latest issues/incidents with quite good reports. Another quite good page is the Aviation Safety Network [2], which can provide you an overview of incidents for each year – which can be drilled down on the individual countries. If you are not a pilot please take in mind that flying is still the most safest way to travel. Businessinsider [3] gives you 12 reason for it.

Happy landings to all of you!

[1] The Aviation Herald

[2] Aviation Safety Network

[3], Flying is still the safest way to travel

Howto start with Bitcoin

Within the last months I have heard a lot about Bitcoin. So I thought to get a bit into this topic. According to Wikipedia [1] it is a decentralized cryptocurrency. The main advantages are basically that the currency is managed decentral, meaning that there are basically no banks required to do any transaction. In addition the transaction costs are basically very low [2], while for certain services (e.g. faster processing) costs can be higher. A good detailed describtion of the Bitcoin transaction fee logic can be found at [3].

For a start I would refer to the official bitcoin homepage [4], where you can find a quick intro. To start you will definitely require a wallet – either you do it on your own, by installing a bitcoin client or you take a wallet from an online account e.g. from blockchain [5]. Since a local installation provides more independency, it also has the risk of loosing bitcoins whenever your computer gets lost/stolen or hacked. With the online version, you usually also have tools and apps available to access your wallet every time and everywhere (e.g. if you like to pay something with your mobile).

Once you have a wallet – you need to find a way to get bitcoins. Ways to get bitcoins are the following ones, which are described in more detail below:

  • Bitcoin Mining
  • bitcoin faucet
  • Earn bitcoins
  • Buy bitcoins

Bitcoin Mining

Bitcoin mining is a nice idea to earn money – but you are years too late. It was only profitable in the beginning, while nowadays you can forget the cost income ratio due to the need for special hardware and high energy costs which are not compensated by the bitcoins you earn.

Bitcoin Faucet

These are basically pages which are showing you advertisements for bitcoins. Most of the pages (e.g. [6]) you earn some Satoshi every 5 minutes. Other ones e.g. moonbit [7] are collecting Satoshi over the time, which you are able to claim every 5 min. While the first one triggers the payout after 30 bits, the second one does a payment once a week when more than 5000 Satoshi are reached. I’ve tried both, and both are working fine. The only thing which should be highlighted – after collecting Satoshi’s over one week, I have not more than 0,1 EUR. That is not much to spend for watching tons of ads.

Earn bitcoins

There are pages like coinworker [8], where you receive bitcoins, once you have completed some tasks, which are mainly surveys. This work out fine, except, that for most of the task you have to reach a specific level, which goes with the amount of completed tasks and a certain quality. So once you start there, it takes ages to get to this level, since in the beginning most of the time there are no tasks available. The earnings are higher than on the Bitcoin faucet pages, but still you will not get rich.

Buy bitcoins

The best suggestion to get bitcoins is to buy them. This can be done either via local bitcoin platforms, where you can buy from real-life persons [9] or you go over a platform like coinbase [10], where you have to register yourself with an official ID and transfer some EUR/USD to buy some bitcoins. Of course you can pay with a credit card as well, but the transaction costs are higher. While the first method might be more convenient, the second option seems to provide better rates for the exchange. But there are of course plenty of other platforms available.

Once you have some bitcoins you can start spending them. There are a pages available [11] which shows you where you can spend you bitcoins. As the currency is quite new, decentral, and partly not legally accepted, the amount of places to spend is limited. But as we are living in a digital world, I am sure there are enough online place to spend them.

While Bitcoin is the best known crypto currency, there are plenty more digital currencies (also known as altcoin) available. A page which provides a quite good overview is coinmarketcap [12] providing details, information regarding rate and liquidity, but also market places where to buy and sell.

There are some issues and problems I see with digital currencies, which I would like to highlight at the end:

  • Personal wallets (like Bitcoin Core): this wallets are bound to your PC and once your computer is hacked or your PC is gone, your virtual money is gone as well.
  • Tax: I know nobody wants to pay tax, but considering that you are trading on Bitcoin Exchanges, taxes on capital income should apply.
  • Monetary control: while some see it as an advantage that there is no currency control available by any kind of government, it might also come with some disadvantages. Since the mining continuously produces more bitcoins, there is no way to reduce the amount – meaning that over time there must be a devaluation.
  • Volatility: Bitcoin has a high volatility, meaning which you could be a lucky bird and earn a lot, you could also lose a lot.
  • Shops: the amount of “real-life” shops is limited.


[1], Bitcoin

[2] Bitcoin Wiki, Transaction Fees

[3], Bitcoin Transaction Fees Explained