Systemd

This is a quick note to list failed services on systemd system. [root@zilla ~]# systemctl status ● zilla State: degraded Jobs: 0 queued Failed: 1 units Since: Fri 2020-09-04 02:20:47 AEST; 3 months 11 days ago CGroup: / ├─1 /usr/lib/systemd/systemd --system --deserialize 22 └─system.slice ├─httpd.service │ ├─21860 /usr/sbin/httpd -DFOREGROUND │ ├─21861 /usr/sbin/httpd -DFOREGROUND │ ├─21862 /usr/sbin/httpd -DFOREGROUND │ ├─21863 /usr/sbin/httpd -DFOREGROUND │ ├─21864 /usr/sbin/httpd -DFOREGROUND │ └─21865 /usr/sbin/httpd -DFOREGROUND ... [root@zilla ~]# systemctl list-units --failed UNIT LOAD ACTIVE SUB DESCRIPTION ● ipmi.service loaded failed failed IPMI Driver LOAD = Reflects whether the unit definition was properly loaded. ACTIVE = The high-level unit activation state, i.e. generalization of SUB. SUB = The low-level unit activation state, values depend on unit type. 1 loaded units listed. Pass --all to see loaded but inactive units, too. To show all installed unit files use 'systemctl list-unit-files'. Or ...

“Bad boys, whatcha want. Watcha want, whatcha gonna do when the root is full?” Actually, what are you gonna do when the journald taking up lots of space? For example, during the operating system upgrade on my desktop, the free space on / is not sufficient. Error Summary ------------- Disk Requirements: At least 5643MB more space needed on the / filesystem. So, I check how much space the systemd-journald log was consuming: ...

On RHEL 7/8, CentOS 7/8 and even Ubuntu (??), by default the journal log data is stored only in memory (/run/log/journal/ directory). There are 2 ways to retain the journal log messages. The first one is to set the variable Storage to persistent in the /etc/systemd/journald.conf. [Journal] Storage=persistent Then restart the systemd-journald service. Another solution is simpler and it looks like it’s the recommended way of achieving this. All we have to do is to create a directory, /var/log/journal (with correct ownership and permission), and journald will automatically store the log messages there. ...

This is just a quick note to remind myself how to enable or disable services using Systemd. In this example, I’m using denyhosts service. Check if a service is running. # systemctl status denyhosts denyhosts.service - SSH log watcher Loaded: loaded (/usr/lib/systemd/system/denyhosts.service; disabled) Active: inactive (dead) Start a service and verify its running status: # systemctl start denyhosts # systemctl status denyhosts denyhosts.service - SSH log watcher Loaded: loaded (/usr/lib/systemd/system/denyhosts.service; disabled) Active: active (running) since Thu 2014-07-17 01:44:29 EDT; 1min 25s ago Process: 15722 ExecStart=/usr/bin/denyhosts.py --daemon --config=/etc/denyhosts.conf (code=exited, status=0/SUCCESS) Process: 15719 ExecStartPre=/bin/rm -f /run/lock/subsys/denyhosts (code=exited, status=0/SUCCESS) Main PID: 19367 (denyhosts.py) CGroup: /system.slice/denyhosts.service └─19367 /usr/bin/python /usr/bin/denyhosts.py --daemon --config=/etc/denyhosts.conf Jul 17 01:44:29 pidora.local systemd[1]: PID file /run/lock/subsys/denyhosts not readable (yet?) after start. Jul 17 01:44:29 pidora.local systemd[1]: Started SSH log watcher. Check if a denyhosts service is enabled or not: ...