Linux Tips

 The disk of my Ubuntu 20.04 used for development was originally 20Gb, and I increased it to 30GB a while ago. This time, the capacity was insufficient again, so I increased it to 50 GB. Every time I did this work, I had a hard time, so I'm going to leave it as a simple post so that I don't repeat the trouble afterwards. The following is a disk with 30 GB status. The usage is 50%. However, this is because there was not enough disk and the files were temporarily moved to another location. After increasing the disk capacity, the backed up files will be imported again. root@ubuntusrv:~# df -h Filesystem Size Used Avail Use% Mounted on udev 937M 0 937M 0% /dev tmpfs 196M 1.3M 195M 1% /run /dev/mapper/ubuntu--vg-ubuntu--lv 29G 14G 14G 50% / tmpfs 980M 0 980M 0% /dev/shm tmpfs 5.0M 0 5.0M 0% /run/lock tmpfs ...

 There are several ways to manage processes on a Linux system. Most important processes are managed as daemon processes. However, since the daemon process is only a process whose parent process is init (pid = 1), the service provided by the process is terminated when abnormally terminated. Therefore, many IT system administrators monitor critical processes. For such monitoring, management tools such as Zabbix are sometimes used. Zabbix can monitor networks, servers, virtual machines and cloud services, and it can even automatically trigger an alarm when a number that exceeds the limits set by the administrator is detected.  While managing these large systems is important, monitoring critical processes on smaller servers and automatically restarting them upon specified shutdown is equally important. monit is a great tool to do this. It is easy to install and very light compared to packages such as Zabbix. Note that monit only works on the server where the pa...