Author Archives: dmitriano

Configuring Oracle Database for Auditing.

To enable Unified Auditing in Oracle Database 12 and 18 on Oracle Linux I did this:

./sqlplus sys as sysdba
./lsnrctl stop
cd $ORACLE_HOME/rdbms/lib
make -f uniaud_on ioracle
./lsnrctl start
./sqlplus sys as sysdba

Running Oracle 18 database in a docker container on Ubuntu 18.04.

Clone the repository with the official Oracle docker images:

git clone

Install docker, download Oracle Database, put it to the directory docker-images/OracleDatabase/SingleInstance/dockerfiles/18.3.0 containing the Dockerfile and run the following commands to build and run Enterprise Edition:

cd docker-images/OracleDatabase/SingleInstance/dockerfiles/18.3.0
mv ~/Downloads/ .
sudo docker build -t oracle/database:18.3.0 --build-arg DB_EDITION=EE .
sudo docker run -d -it --rm --name oracle18 oracle/database:18.3.0
sudo docker logs oracle18 --tail 100
sudo docker logs oracle18 | grep -i password

and the following commands to build and run Standard Edition 2:

sudo docker build -t oracle/database-se:18.3.0 --build-arg DB_EDITION=SE2 .
sudo docker run -d -it --rm --name oracle18se oracle/database-se:18.3.0
sudo docker logs oracle18se --tail 100

the first string of the docker output contains the generated password for SYS, SYSTEM and PDBADMIN.


Mining BEAM with GeForce GTX 1060 3GB on HiveOS

It is still possible to mine BEAM with GeForce GTX 1060 3GB and GMiner on HiveOS. GMiner takes 2862MB on GPU0 and 2850MiB on GPU1-7:


Building and running rippled on Ubuntu.

I successfully build and run rippled 1.1.2 on Ubuntu 18.04 with the following commands:

sudo apt-get -y install git cmake pkg-config protobuf-compiler libprotobuf-dev libssl-dev wget
cd ~Downloads/
cd ..
mkdir lib
cd lib/
tar xvzf ~/Downloads/boost_1_67_0.tar.gz
./b2 -j1
export BOOST_ROOT=/home/user/lib/boost_1_67_0
cd ~/repos/
git clone
cd rippled
git tag
git show --summary 1.1.2
git reset --hard 1.1.2
mkdir build
cd build/
cmake ..
cmake --build .
./rippled -u

Setting up time synchronization on Ubuntu

I followed the official Ubuntu time synchronization guide and installed chrony:

sudo apt update
sudo apt install chrony
cat /etc/chrony/chrony.conf
chronyc sources
chronyc sourcestats
sudo systemctl restart chrony.service
apt remove --autoremove chrony


Setting up Ethereum node on Windows 10 and Ubuntu.

After a few attempts I was able to start Ethereum Mist 0.11.1 in ‘fast’ mode on Windows 10:

it downloaded ‘geth’, connected to {“path”:”\\\\.\\pipe\\geth.ipc”} and started to sync, but when sync finished I was unable to send transactions (they were ‘denied’ for some reason).


Checking the speed of my home internet.

I have 50 Mbit internet at home. If I test its speed with I get download speed 56 Mbit/s and upload speed 5.56 Mbit/s that is really good:

and if I download a file with torrent the speed is 6+ MB/s, but if I download a file with HTTP or SFTP the speed can be less than 500 KB/s that is 10 times slower. For example, if I download Ubuntu 18.10 on my VPS the speed is 24 MB/s:


Setting up Vue.js development tools on Windows 10.

I installed Node.js and Vue.js cli with the following commands

npm install -g @vue/cli
npm install -g @vue/cli-init

and a sample application with

vue init webpack-simple my-vue-app
cd my-vue-app
npm install
npm run dev


Some GTX 1060 3GB cards have low hashrate with Ethash coins.

Ethash algorithm behaves a bit strange on my mining rig with HiveOS and 8 GTX 1060 3GB. Four MSI ARMOR cards with Sumsung memory (OC +1500 mem) have 24+ MH/s, two other cards (OC +600 mem) have 21+ MH/s and two other slow MSI cards (also OC +600 mem) have only 18+ MH/s. I tried to switch risers, PSU, PCI slots and move the cards across rigs, but with no success.

Today I did a pure experiment. I plugged one of the slow cards to a Windows 10 machine with 1000W PSU directly via PCI slot without riser, started Claymore Miner with Musicoin (that has a lower dag size than Ethereum) and got the same result as before, without OC the card had 15+ MH/s (normally it should be 19+ MH/s):


Molten SATA power connector on a mining rig.

I have a mining rig with 8 GTX 1060 3GB connected via risers, the risers are connected via SATA power connectors to Corsair HX850. When the rig stopped working I noticed that one SATA connector on the PSU is molten: