Vez ou outra ficamos na dúvida se a cron (serviço para executar comandos agendados no Linux) está habilitada ou não, e se o seu daemon está em execução. Isso é muito simples, conforme exemplos abaixo:
Validar se o serviço está habilitado:
[root@oel7 system]# systemctl is-enabled crond
enabled
Validar se o serviço está em execução:
[root@oel7 system]# systemctl status crond
● crond.service - Command Scheduler
Loaded: loaded (/usr/lib/systemd/system/crond.service; enabled; vendor preset: enabled)
Active: active (running) since Thu 2022-06-30 19:31:07 -03; 20min ago
Main PID: 1952 (crond)
Tasks: 1
CGroup: /system.slice/crond.service
└─1952 /usr/sbin/crond -n
Jun 30 19:31:07 oel7.localdomain systemd[1]: Started Command Scheduler.
Jun 30 19:31:08 oel7.localdomain crond[1952]: (CRON) INFO (RANDOM_DELAY will be scaled with fa...d.)
Jun 30 19:31:09 oel7.localdomain crond[1952]: (CRON) INFO (running with inotify support)
Hint: Some lines were ellipsized, use -l to show in full.
[root@oel7 system]#
Desabilitar o serviço (para que não suba automaticamente no próximo boot):
[root@oel7 system]# systemctl disable crond
Removed symlink /etc/systemd/system/multi-user.target.wants/crond.service.
[root@oel7 system]#
Habilitando o serviço:
[root@oel7 system]# systemctl enable crond
Created symlink from /etc/systemd/system/multi-user.target.wants/crond.service to /usr/lib/systemd/system/crond.service.
[root@oel7 system]#
Baixando o serviço e consultando:
[root@oel7 system]# systemctl stop crond
[root@oel7 system]# systemctl status crond
● crond.service - Command Scheduler
Loaded: loaded (/usr/lib/systemd/system/crond.service; enabled; vendor preset: enabled)
Active: inactive (dead) since Thu 2022-06-30 19:54:17 -03; 9s ago
Process: 1952 ExecStart=/usr/sbin/crond -n $CRONDARGS (code=exited, status=0/SUCCESS)
Main PID: 1952 (code=exited, status=0/SUCCESS)
Jun 30 19:31:07 oel7.localdomain systemd[1]: Started Command Scheduler.
Jun 30 19:31:08 oel7.localdomain crond[1952]: (CRON) INFO (RANDOM_DELAY will be scaled with fa...d.)
Jun 30 19:31:09 oel7.localdomain crond[1952]: (CRON) INFO (running with inotify support)
Jun 30 19:54:17 oel7.localdomain systemd[1]: Stopping Command Scheduler...
Jun 30 19:54:17 oel7.localdomain systemd[1]: Stopped Command Scheduler.
Hint: Some lines were ellipsized, use -l to show in full.
[root@oel7 system]#
Subindo o serviço e consultando:
[root@oel7 system]# systemctl start crond
[root@oel7 system]# systemctl status crond
● crond.service - Command Scheduler
Loaded: loaded (/usr/lib/systemd/system/crond.service; enabled; vendor preset: enabled)
Active: active (running) since Thu 2022-06-30 19:55:11 -03; 3s ago
Main PID: 5447 (crond)
Tasks: 1
CGroup: /system.slice/crond.service
└─5447 /usr/sbin/crond -n
Jun 30 19:55:11 oel7.localdomain systemd[1]: Started Command Scheduler.
Jun 30 19:55:11 oel7.localdomain crond[5447]: (CRON) INFO (RANDOM_DELAY will be scaled with fa...d.)
Jun 30 19:55:11 oel7.localdomain crond[5447]: (CRON) INFO (running with inotify support)
Jun 30 19:55:11 oel7.localdomain crond[5447]: (CRON) INFO (@reboot jobs will be run at compute...p.)
Hint: Some lines were ellipsized, use -l to show in full.
Reiniciando o serviço:
[root@oel7 system]# systemctl restart crond