There are many ways and tools to check and list all running services in Linux. Usually most of the administrator use `service service-name status` or `/etc/init.d/service-name status` for sysVinit system and `systemctl status service-name` for systemd systems.
The above command clearly shows that the mentioned service is running on server or not. It is very simple and basic command that should known by every Linux administrator.
If you are new to your environment and you don’t know what services are running on the system. How do you check?
Yes, we can check this. This will will help us to understand what are the services are running on the system and whether it’s necessary or need to disable.
### What Is SysVinit
init (short for initialization) is the first process started during booting of the computer system. Init is a daemon process that continues running until the system is shut down.
SysVinit is an old and traditional init system and system manager for old systems. Most of the latest distributions were adapted to systemd system due to some of the long pending issues on sysVinit system.
### What Is systemd
systemd is a new init system and system manager which is become very popular and widely adapted new standard init system by most of Linux distributions. Systemctl is a systemd utility which is help us to manage systemd system.
### Method-1: How To Check Running Services In sysVinit System
The below command helps us to check and list all running services in sysVinit system.
If you have many number of services, i would advise you to use file view commands such as less, more, etc commands for clear view.
```
# service --status-all
or
# service --status-all | more
or
# service --status-all | less
abrt-ccpp hook is installed
abrtd (pid 2131) is running...
abrt-dump-oops is stopped
acpid (pid 1958) is running...
atd (pid 2164) is running...
auditd (pid 1731) is running...
Frequency scaling enabled using ondemand governor
crond (pid 2153) is running...
hald (pid 1967) is running...
htcacheclean is stopped
httpd is stopped
Table: filter
Chain INPUT (policy ACCEPT)
num target prot opt source destination
1 ACCEPT all ::/0 ::/0 state RELATED,ESTABLISHED
2 ACCEPT icmpv6 ::/0 ::/0
3 ACCEPT all ::/0 ::/0
4 ACCEPT tcp ::/0 ::/0 state NEW tcp dpt:80
5 ACCEPT tcp ::/0 ::/0 state NEW tcp dpt:21
6 ACCEPT tcp ::/0 ::/0 state NEW tcp dpt:22
7 ACCEPT tcp ::/0 ::/0 state NEW tcp dpt:25
8 ACCEPT tcp ::/0 ::/0 state NEW tcp dpt:2082
9 ACCEPT tcp ::/0 ::/0 state NEW tcp dpt:2086
10 ACCEPT tcp ::/0 ::/0 state NEW tcp dpt:2083
11 ACCEPT tcp ::/0 ::/0 state NEW tcp dpt:2087
12 ACCEPT tcp ::/0 ::/0 state NEW tcp dpt:10000
13 REJECT all ::/0 ::/0 reject-with icmp6-adm-prohibited
Chain FORWARD (policy ACCEPT)
num target prot opt source destination
1 REJECT all ::/0 ::/0 reject-with icmp6-adm-prohibited
Chain OUTPUT (policy ACCEPT)
num target prot opt source destination
iptables: Firewall is not running.
irqbalance (pid 1826) is running...
Kdump is operational
lvmetad is stopped
mdmonitor is stopped
messagebus (pid 1929) is running...
SUCCESS! MySQL running (24376)
rndc: neither /etc/rndc.conf nor /etc/rndc.key was found
named is stopped
netconsole module not loaded
Usage: startup.sh { start | stop }
Configured devices:
lo eth0 eth1
Currently active devices:
lo eth0
ntpd is stopped
portreserve (pid 1749) is running...
master (pid 2107) is running...
Process accounting is disabled.
quota_nld is stopped
rdisc is stopped
rngd is stopped
rpcbind (pid 1840) is running...
rsyslogd (pid 1756) is running...
sandbox is stopped
saslauthd is stopped
smartd is stopped
openssh-daemon (pid 9859) is running...
svnserve is stopped
vsftpd (pid 4008) is running...
xinetd (pid 2031) is running...
zabbix_agentd (pid 2150 2149 2148 2147 2146 2140) is running...
```
Run the following command to view only running services in the system.
```
# service --status-all | grep running
crond (pid 535) is running...
httpd (pid 627) is running...
mysqld (pid 911) is running...
rndc: neither /etc/rndc.conf nor /etc/rndc.key was found
rsyslogd (pid 449) is running...
saslauthd (pid 492) is running...
sendmail (pid 509) is running...
sm-client (pid 519) is running...
openssh-daemon (pid 478) is running...
xinetd (pid 485) is running...
```
Run the following command to view the particular service status.
```
# service --status-all | grep httpd
httpd (pid 627) is running...
```
Alternatively use the following command to view the particular service status.
```
# service httpd status
httpd (pid 627) is running...
```
Use the following command to view the list of running services enabled in boot.
Mar 06 12:34:08 magi-VirtualBox systemd[1]: Starting The Apache HTTP Server...
Mar 06 12:34:09 magi-VirtualBox apachectl[1089]: AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 10.0.2.15. Set the 'ServerName' directive globally to suppre
Mar 06 12:34:09 magi-VirtualBox systemd[1]: Started The Apache HTTP Server.
Mar 06 12:39:10 magi-VirtualBox systemd[1]: Reloading The Apache HTTP Server.
Mar 06 12:39:10 magi-VirtualBox apachectl[2786]: AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using fe80::7929:4ed1:279f:4d65. Set the 'ServerName' directive gl
Mar 06 12:39:10 magi-VirtualBox systemd[1]: Reloaded The Apache HTTP Server.
```
Run the following command to view only running services in the system.
```
# systemctl | grep running
acpid.path loaded active running ACPI Events Check
cups.path loaded active running CUPS Scheduler
init.scope loaded active running System and Service Manager
session-c2.scope loaded active running Session c2 of user magi
accounts-daemon.service loaded active running Accounts Service
acpid.service loaded active running ACPI event daemon
apache2.service loaded active running The Apache HTTP Server
aptik-battery-monitor.service loaded active running LSB: start/stop the aptik battery monitor daemon
atop.service loaded active running Atop advanced performance monitor
atopacct.service loaded active running Atop process accounting daemon
avahi-daemon.service loaded active running Avahi mDNS/DNS-SD Stack
colord.service loaded active running Manage, Install and Generate Color Profiles
cron.service loaded active running Regular background program processing daemon
cups-browsed.service loaded active running Make remote CUPS printers available locally
cups.service loaded active running CUPS Scheduler
dbus.service loaded active running D-Bus System Message Bus
fwupd.service loaded active running Firmware update daemon
[emailprotected] loaded active running Getty on tty1
irqbalance.service loaded active running LSB: daemon to balance interrupts for SMP systems
lightdm.service loaded active running Light Display Manager
ModemManager.service loaded active running Modem Manager
NetworkManager.service loaded active running Network Manager
polkit.service loaded active running Authorization Manager
```
Use the following command to view the list of running services enabled in boot.
```
# systemctl list-unit-files | grep enabled
acpid.path enabled
cups.path enabled
accounts-daemon.service enabled
anacron-resume.service enabled
anacron.service enabled
apache2.service enabled
apparmor.service enabled
atop.service enabled
atopacct.service enabled
[emailprotected] enabled
avahi-daemon.service enabled
bluetooth.service enabled
console-setup.service enabled
cron.service enabled
cups-browsed.service enabled
cups.service enabled
display-manager.service enabled
dns-clean.service enabled
friendly-recovery.service enabled
[emailprotected] enabled
gpu-manager.service enabled
keyboard-setup.service enabled
lightdm.service enabled
ModemManager.service enabled
network-manager.service enabled
networking.service enabled
NetworkManager-dispatcher.service enabled
NetworkManager-wait-online.service enabled
NetworkManager.service enabled
```
systemd-cgtop show top control groups by their resource usage such as tasks, CPU, Memory, Input, and Output.
