Fedora 27 : Fix your distro with systemctl .

This is a simple tutorial about systemctl tool and how to fix one simple error show by status. The help of this cmmand can be found with:

# man systemctl

Let's see how we can see this errors and how this working. First let's see the status for systemctl command (:

# systemctl status

The output is this:

    ● laptop
    State: degraded
     Jobs: 0 queued
   Failed: 1 units
    Since: Sun 2018-04-01 10:44:37 EEST; 58min ago
   CGroup: /
           ├─user.slice
           │ └─user-1000.slice
           │   ├─user@1000.service
           │   │ └─init.scope
           │   │   ├─929 /usr/lib/systemd/systemd --user
           │   │   └─931 (sd-pam)
           │   └─session-1.scope
           │     ├─ 748 login -- mythcat
           │     ├─ 936 -bash
           │     ├─ 982 sudo su
           │     ├─ 986 su
           │     ├─ 987 bash
           │     └─9879 systemctl status
           ├─init.scope
           │ └─1 /usr/lib/systemd/systemd --switched-root --system --deserialize 24
           └─system.slice
             ├─irqbalance.service
             │ └─655 /usr/sbin/irqbalance --foreground
             ├─lvm2-lvmetad.service
             │ └─578 /usr/sbin/lvmetad -f -t 3600
             ├─firewalld.service
             │ └─698 /usr/bin/python3 -Es /usr/sbin/firewalld --nofork --nopid
 ...

Detect the problem from list all failed units:

# systemctl list-units --state=failed

I find the rngd module is the problem. To fix this issue just use this commands:

# systemctl daemon-reload
# systemctl status rngd 
# systemctl stop rngd
# systemctl disable rngd
# systemctl enable rngd
# systemctl start rngd

The next step is reboot and check again if systemctl come with errors.