The following error occurred a lot in /var/log/nginx/error.log:
Too many open files
This means that the nginx master process reached the maximum number of open files which was set to the default of 4096. (To check it, simply cat /proc/pid/limits, where pid is the process id)
To resolve, this, edit /lib/systemd/system/nginx.service and add the following line:
LimitNOFILE=30000 #change it according to your needs
Then reload the systemctl daemon:
sudo systemctl daemon-reload
and finally restart the nginx service:
sudo service nginx restart
That’s it, the error is gone!
Tested on Ubuntu 16.04 with nginx 1.17, should work with any other OS using systemd.
Enjoy!
Sources:
Firstly, install scsitools package:
sudo apt install scsitools
Then run the command rescan-scsi-bus:
sudo rescan-scsi-bus
That’s it, your new virtual HDD has now been detected.
Another way would be to do it with a loop and without the need for that package:
for host inls /sys/class/scsi_host/; do
echo "- - -" > /sys/class/scsi_host/${host}/scan;
done
Enjoy!
Sources:
A very handy screenshot tool that works very well on my KDE plasma desktop on Ubuntu 19.10 is ksnip, which you can get from here: https://github.com/damirporobic/ksnip
Just download and install the deb file and that’s it!
Enjoy!
sudo service NetworkManager restart
Note: This is specifically for the network icon in the system tray and is different from the network-manager service which controls the whole Linux network manager:
Tested on Ubuntu 19.10 with KDE Plasma 5.16.5
From remote server to local one:
rsync -avzhe ssh remote_user@REMOTE_IP:/remote_folder_or_file /local_destination_folder_or_file
From local server to remote one:
rsync -avzhe ssh local_folder_or_file remote_user@REMOTE_IP:/remote_destination_folder_or_file
That’s it, Enjoy!
Sources:
Rsync (Remote Sync): 10 Practical Examples of Rsync Command in Linux
Synergy software, which shares your keyboard and mouse to multiple computers through the network, is no longer available in the Ubuntu 19.04 repos, so the only remaining option is to build it from source:
sudo apt install qtcreator qtbase5-dev cmake make g++ xorg-dev libssl-dev libx11-dev libsodium-dev libgl1-mesa-glx libegl1-mesa libcurl4-openssl-dev libavahi-compat-libdnssd-dev qtdeclarative5-dev libqt5svg5-dev libsystemd-dev git build-essential git clone https://github.com/symless/synergy-core.git cd synergy mkdir build cd build cmake .. make sudo make install
That’s it, Enjoy!
Note: After starting Synergy, you don’t have to enter the serial to get basic functionality, just cancel and you are good to go.
Source: https://github.com/symless/synergy-core/wiki/Compiling
