Notes
pico doesn't go with Centos.
As result you can get something like the following:
crontab -e /bin/sh: pico: command not found crontab: "pico" exited with status 127
To get rid of this error, do the following:
Install nano editor if needed:
yum install nano -y
And run:
cd /usr/bin/ ln -s nano pico export EDITOR="pico"… Read the rest
You should never terminate atop by 'kill -9', because then it has no chance to stop process accounting; as a result the accounting file may consume a lot of disk space after a while!!!
Lets do this smoothly:
systemctl stop atopd systemctl disable atopd Check atop processes ps auxfS |grep atop Kill if any using 'kill -15' kill -15 PID
Check for links and unlink if any:
ls /etc/systemd/system/ |grep atop
Remove atopd.service… Read the rest
ssh-keyscan -t rsa YOUR_SERVERs_IP_ADDRESS_OR_HOSTNAME
Output:
# YOUR_SERVERs_IP_ADDRESS_OR_HOSTNAME:22 SSH-2.0-OpenSSH_5.3
YOUR_SERVERs_IP_ADDRESS_OR_HOSTNAME ssh-rsa AAAAB3NzaC1yc...
Check with the several type of the keys:
ssh-keyscan -t rsa1,rsa,dsa,ecdsa,ed25519 YOUR_SERVERs_IP_ADDRESS_OR_HOSTNAME… Read the rest Run from a command line:
export EDITOR=/bin/vi export VISUAL=vi
or
export EDITOR=/usr/bin/vim export VISUAL=vim
or
export EDITOR=/bin/nano export VISUAL=nano… Read the rest
Install nc if needed
yum install nc
Run listener on port 3000
nc -l 3000 & nc -l -k 3000 &
where -k is –keep-open will keep connection opened and allows multiple connections in listen mode
Check on the server’s side:
netstat -tunap |grep :3000
Output:
tcp 0 0 0.0.0.0:3000 0.0.0.0:* LISTEN 82786/nc
Check from local machine:
$ nmap -p 3000 SERVERS_IP_ADDRESS
Output:
Starting Nmap 7.01 ( https://nmap.org… Read the rest
tmpwatch – removes files which haven't been accessed for a period of time
echo '0 2 * * * /usr/sbin/tmpwatch -d -l -m 24 /tmp' >> /var/spool/cron/root… Read the rest
View your current timezone's settings: date timedatectl status
Find your timezone from the list using command below:
timedatectl list-timezonesUpdate your timezone:
sudo timedatectl set-timezone Europe/KievCheck:
date… Read the rest Backup your current settings if needed
cp -rp .mozilla/ .mozilla_bk
Purge current firefox
sudo apt-get purge firefox -y
Download 56 version
wget https://ftp.mozilla.org/pub/firefox/releases/56.0/linux-x86_64/en-US/firefox-56.0.tar.bz2 sudo su tar -xvf firefox-56.0.tar.bz2 cp -rp firefox /opt/ cd /usr/bin ln -s /opt/firefox/firefox firefox
Finally, you have to avoid upgrading to the newer version.… Read the rest
You need to have ffmpeg installed:
ffmpeg -i input.mp4 -vcodec libx264 -crf 20 output.mp4 ffmpeg -i input.mp4 -b 1000000 output.mp4 ffmpeg -i input.mp4 -b 700000 output.mp4… Read the rest