On running “apt upgrade” command on Ubuntu 20.04 and newer, Ubuntu shows an advertisement about Ubuntu Pro subscription.
To disable the Ubuntu Pro advertisement that appears when updating apt, run
sudo mv /etc/apt/apt.conf.d/20apt-esm-hook.conf /etc/apt/apt.conf.d/20apt-esm-hook.conf.bak
sudo touch /etc/apt/apt.conf.d/20apt-esm-hook.confAfter running these commands, running “apt upgrade”, you won’t get the Ubuntu Pro advertisement.
Back to Ubuntu
MySQL 5.7 is not supported on Ubuntu 22.04, but you can download MySQL 5.7 for Ubuntu 18.04 and install it on Ubuntu 20.04 or Ubuntu 22.04
First, install libtinfo5, this is available for download from https://launchpad.net/ubuntu/bionic/amd64/libtinfo5/6.1-1ubuntu1.18.04
cd ~/
wget http://launchpadlibrarian.net/371711898/libtinfo5_6.1-1ubuntu1.18.04_amd64.deb
dpkg -i libtinfo5_6.1-1ubuntu1.18.04_amd64.debThe files are moved from the Offical MySQL site
https://dev.mysql.com/downloads/mysql/5.7.html
So we will download it from a mirror site. If the mirror is down, you can search with the .deb file name to find another mirror.
mkdir ~/mysql57
cd ~/mysql57
wget https://mirror.csclub.uwaterloo.ca/mysql/Downloads/MySQL-5.7/libmysqlclient-dev_5.7.38-1ubuntu18.04_amd64.deb
wget https://mirror.csclub.uwaterloo.ca/mysql/Downloads/MySQL-5.7/libmysqlclient20_5.7.38-1ubuntu18.04_amd64.deb
wget https://mirror.csclub.uwaterloo.ca/mysql/Downloads/MySQL-5.7/libmysqld-dev_5.7.38-1ubuntu18.04_amd64.deb
wget https://mirror.csclub.uwaterloo.ca/mysql/Downloads/MySQL-5.7/mysql-client_5.7.38-1ubuntu18.04_amd64.deb
wget https://mirror.csclub.uwaterloo.ca/mysql/Downloads/MySQL-5.7/mysql-common_5.7.38-1ubuntu18.04_amd64.deb
wget https://mirror.csclub.uwaterloo.ca/mysql/Downloads/MySQL-5.7/mysql-community-client_5.7.38-1ubuntu18.04_amd64.deb
wget https://mirror.csclub.uwaterloo.ca/mysql/Downloads/MySQL-5.7/mysql-community-server_5.7.38-1ubuntu18.04_amd64.deb
wget https://mirror.csclub.uwaterloo.ca/mysql/Downloads/MySQL-5.7/mysql-community-source_5.7.38-1ubuntu18.04_amd64.deb
wget https://mirror.csclub.uwaterloo.ca/mysql/Downloads/MySQL-5.7/mysql-community-test_5.7.38-1ubuntu18.04_amd64.deb
wget https://mirror.csclub.uwaterloo.ca/mysql/Downloads/MySQL-5.7/mysql-server_5.7.38-1ubuntu18.04_amd64.deb
wget https://mirror.csclub.uwaterloo.ca/mysql/Downloads/MySQL-5.7/mysql-testsuite_5.7.38-1ubuntu18.04_amd64.deb
dpkg -i *.deb
apt install -fTo start MySQL on boot, run
systemctl enable mysqlTo start MySQL, run
systemctl start mysqlBack to MySQL Installation
When updating packages on an Ubuntu server, I got the error “Unsafe symlinks encountered in /var/log, refusing.”.
root@ip-172-31-45-33:/var# apt upgrade -y Reading package lists... Done Building dependency tree Reading state information... Done Calculating upgrade... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 1 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Setting up rsyslog (8.32.0-1ubuntu4.2) ... The user `syslog' is already a member of `adm'. Unsafe symlinks encountered in /var/log, refusing. dpkg: error processing package rsyslog (--configure): installed rsyslog package post-installation script subprocess returned error exit status 1 Errors were encountered while processing: rsyslog E: Sub-process /usr/bin/dpkg returned an error code (1) root@ip-172-31-45-33:/var#
This is due to wrong file ownership for /var/log folder.
I found the directory “/var” was owned by user www-data
root@ip-172-31-45-33:/var# ls -l / | grep var drwxr-xr-x 15 www-data www-data 4096 Sep 1 2021 var root@ip-172-31-45-33:/var#
To fix the error I changed ownership of /var directory to root user.
chown root:root /var
IMPORTANT: Do not use chown -R as the /var folder contains files owned by different users, if you change all file/folder ownership to root, it will mess up the system. For example /var/log/mysql need to be owned by user “mysql”, if you change it to the user “root”, MySQL will fail to start.
You may also need to check ownership of folder /var/log and files inside. You can compare it with another Ubuntu server to make sure directory/file ownerships are correct.
Back to apt
First, install libwww-perl package needed for CSF firewall
apt -y install libwww-perl
Install CSF with
cd /usr/local/src wget https://download.configserver.com/csf.tgz tar -xzf csf.tgz cd csf sh install.sh
Change following settings in csf.conf file
/bin/sed -i "s/RESTRICT_SYSLOG\s*=.*$/RESTRICT_SYSLOG = \"3\"/g" /etc/csf/csf.conf /bin/sed -i "s/SYSLOG_CHECK\s*=.*$/SYSLOG_CHECK = \"3600\"/g" /etc/csf/csf.conf /bin/sed -i "s/TESTING = \"1\"/TESTING = \"0\"/g" /etc/csf/csf.conf
If you need GUI enabled, edit file
vi /etc/csf/csf.conf
Modify following settings
UI = "1" UI_PORT = "8282" UI_USER = "username" UI_PASS = "password" UI_ALLOW = "0"
A few days ago I wanted to Migrate an Ubuntu VPS from one provider to another. I tried to take a snapshot and try to migrate, but it did not work. The VPS had few random services, so migrating services one by one was not easy. What I did was set up a new Ubuntu VPS with the same OS version, rsync files from source VPS to new VPS.
Make sure you take a backup of your server before doing it. In case anything goes wrong, you should be able to restore from back or OS reload.
Install rsync on source and destination servers.
For Ubuntu/Debian
apt install rsyncFor RHEL/CentOS/AlmaLinux
yum install rsyncOn the source server, create a file
vi /root/no_copyadd the following content
/boot/
/etc/modules
/etc/fstab
/etc/mtab
/etc/netplan/
/etc/network/
/etc/sysconfig/network-scripts/
/lib/modules
lost+found/
/sys/
/proc/
/dev/
/var/cache/
/var/log/journal/
/swapfile
/swap.img
/usr/tmpDSK
/root/.ssh/
/backup/
/home/virtfs/These files won’t be copied to the new VPS. If you don’t have any other folders or files, that you don’t want to be copied to the new server, you can add to the list.
Now run rsync on the source server to copy over files to the new server
rsync -avzPHAX --exclude-from=/root/no_copy / root@NEW_SERVER_IP:/In the command above, replace NEW_SERVER_IP with the new server IP address.
When we do rsync, all files get copied to the new server. After the first rsync run, you can run the rsync command any number of times, only changed files copied, and will finish much faster as less data need to be copied to the new server.
After the first rsync is completed, we will stop all services on the source and destination servers like MySQL, Apache, Nginx, etc… so no data gets changed while we doing the rsync. Now do another rsync, reboot the destination server, see if everything works fine.
See rsync
To verify the integrity of installed packages, you can use debsums utility. First of all install debsums with command
apt install -y debsums
To verify packages, run
debsums -s
To verify a package
debsums PKG_NAME
If you find any packages with missing files, you can reinstall them with the command
apt reinstall PKG_NAME
WebP is an image format for web by Google. The size of webp images are much smaller compared with other image formats, so better to use webp images on websites for faster site load speed.
To install webp on Ubuntu/Debian, run
sudo apt install webp
To convert an image to webp format, run
cwebp image.png -o image.webp
With the above command, image.png file gets converted to image.webp
You can specify quality with -q option
-q............. quality factor (0:small..100:big), default=75
To view a webp image, run
vwebp image.webp
If you have installed Ubuntu with GUI and don’t want GUI, you can disable GUI from starting on boot with command
systemctl set-default multi-user
If you need to GUI auto-start on boot, run
systemctl set-default graphical.target
When I run locale-gen command, i get the following error
root@netmon1:~# locale-gen en_US.UTF-8 bash: locale-gen: command not found root@netmon1:~#
To see which package provide the locale-gen command, run
boby@sok-01:~$ dpkg -S /usr/sbin/locale-gen locales: /usr/sbin/locale-gen boby@sok-01:~$
The command locale-gen is provided by package locales. To fix the error install package “locales” with the command
apt install -y locales
See locale-gen
To enable firewal for Ant Media Server on Ubnuntu server, use following rules
ufw allow ssh ufw allow http ufw allow https ufw allow 1935/tcp ufw allow 5080/tcp ufw allow 5443/tcp ufw allow 5000:65000/udp enable ufw
After enabling, you will have following status
root@server:~# ufw status Status: active To Action From -- ------ ---- 22/tcp ALLOW Anywhere 80/tcp ALLOW Anywhere 443/tcp ALLOW Anywhere 1935/tcp ALLOW Anywhere 5080/tcp ALLOW Anywhere 5443/tcp ALLOW Anywhere 5000:65000/udp ALLOW Anywhere 22/tcp (v6) ALLOW Anywhere (v6) 80/tcp (v6) ALLOW Anywhere (v6) 443/tcp (v6) ALLOW Anywhere (v6) 1935/tcp (v6) ALLOW Anywhere (v6) 5080/tcp (v6) ALLOW Anywhere (v6) 5443/tcp (v6) ALLOW Anywhere (v6) 5000:65000/udp (v6) ALLOW Anywhere (v6) root@server:~#
You can forward port 80 and 443 to Ant Media Server, so you don’t have to use ports.
You can use following iptables commands
sudo iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 5080 sudo iptables -t nat -A PREROUTING -p tcp --dport 443 -j REDIRECT --to-port 5443
To make it permanent, edit
vi /etc/ufw/before.rules
In the beginning of the file, find
*filter
Add above
*nat :PREROUTING ACCEPT [0:0] -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 5080 -A PREROUTING -p tcp --dport 443 -j REDIRECT --to-port 5443 COMMIT
Restart ufw firewall
ufw disable ufw enable
See Ant Media Server
To reinstall Kernel in Ubunru, you need to find the version of kernal installed, for this run
dpkg -l | grep linux-image
Or you can use command, find the kernel version you need to install
apt-cache search linux-image
Once you have the name of linux-image package you need to install, you can run
apt-get install --reinstall PKG_NAME_HERE
Example
Shotcut is an free open source video editor for Ubuntu. You can find more info at
Latest version of Shotcut video editor can be installed on Ubuntu using command
sudo snap install shotcut --classic
shotcut is also available to be installed from apt, but this is slightly older version than snap. To install from apt, use command
sudo apt install shotcut
See Ubuntu