Category Archives: Linux

Create a filesystem report with Python

In many cases, data accumulates over time, and a lot of this data is not being accessed at all, sometimes for years. Accordingly, it would be great if you could create a report that shows which data, the last access … Continue reading

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Script to count number of logged in users to OpenVPN

To get that information you need to query your openvpn-status.log file, which usually resides in /var/log/openvpn/openvpn-status.log. A normal cat will show the following: OpenVPN CLIENT LIST Updated,Wed Mar 5 11:57:51 2019 Common Name,Real Address,Bytes Received,Bytes Sent,Connected Since someuser,someip:55530,100686479,319036434,Tue Mar 5 … Continue reading

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What to do when ctrl+c not killing your telnet command

To check if ports are open or not, we usually do the following: telnet IP PORT For example: telnet 192.168.100.5 25 Sometimes after seeing your result, you keep pressing ctrl+c, ctrl+x or ctrl+\ to force quit it, but it just … Continue reading

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How to reset display settings for KDE Plasma

In case your display arrangement or settings, e.g. when you have 3 screens and you are for some reason unable to reorganize them or change their settings, just reset your display settings: rm -rf .local/share/kscreen Then just log out and … Continue reading

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How to force resync between PBIS and AD on Linux

In case you made a change on your AD, such as modifying groups or changing attributes of a user, it sometimes take a little while to reflect that on the Linux server that authenticates against AD via PBIS. The best … Continue reading

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How to change max open files for nginx server on Ubuntu

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, … Continue reading

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Add a new HDD to a VM without rebooting on Ubuntu server

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 … Continue reading

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