Tag: linux

You can modify a user’s home directory using usermod command in Linux.

The syntax for the usermod command is

sudo usermod -d PATH_TO_HOME_DIR USER_NAME

Example

I have a user “sok_user1” with home directory /home/sok_user1

root@ok:~# cat /etc/passwd | grep sok_user1
sok_user1:x:1004:1005::/home/sok_user1:/bin/bash
root@ok:~#

To change the users home directory to /var/www/, we can use the command

usermod -d /var/www sok_user1

Example

root@ok:~# usermod -d /var/www sok_user1
root@ok:~# cat /etc/passwd | grep sok_user1
sok_user1:x:1004:1005::/var/www:/bin/bash
root@ok:~# 

Back to Linux User

To list all configured IP addresses on a server, you can use the command

hostname -I

To find the main IP, use

hostname -I | awk '{print $1}'

You can also use the command “ip addr” to list all IP address.

ip addr | grep "inet "

Example

root@server20 [~]# ip addr | grep "inet "
    inet 127.0.0.1/8 scope host lo
    inet 158.69.53.72/24 brd 158.69.53.255 scope global eth0
    inet 158.69.114.170/32 brd 158.69.114.170 scope global eth0:cp1
    inet 54.39.173.35/32 brd 54.39.173.35 scope global eth0:cp2
root@server20 [~]# 

Another command that lists IP address is ifconfig


root@server20 [~]# ifconfig
eth0: flags=4163  mtu 1500
        inet 158.69.53.72  netmask 255.255.255.0  broadcast 158.69.53.255
        inet6 fe80::ec4:7aff:fe69:9342  prefixlen 64  scopeid 0x20
        inet6 2607:5300:60:8248::  prefixlen 64  scopeid 0x0
        ether 0c:c4:7a:69:93:42  txqueuelen 1000  (Ethernet)
        RX packets 3423724119  bytes 670412248418 (624.3 GiB)
        RX errors 0  dropped 0  overruns 18691  frame 0
        TX packets 3843828868  bytes 3897383743022 (3.5 TiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device memory 0xfb120000-fb13ffff  

eth0:cp1: flags=4163  mtu 1500
        inet 158.69.114.170  netmask 255.255.255.255  broadcast 158.69.114.170
        ether 0c:c4:7a:69:93:42  txqueuelen 1000  (Ethernet)
        device memory 0xfb120000-fb13ffff  

eth0:cp2: flags=4163  mtu 1500
        inet 54.39.173.35  netmask 255.255.255.255  broadcast 54.39.173.35
        ether 0c:c4:7a:69:93:42  txqueuelen 1000  (Ethernet)
        device memory 0xfb120000-fb13ffff  

lo: flags=73  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 3364258789  bytes 4360941211553 (3.9 TiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 3364258789  bytes 4360941211553 (3.9 TiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

root@server20 [~]# 

On a remote Linux server running XFCE desktop, the server goes down randomly, on monitoring /var/log/syslog, i found the following message

Jan 18 05:43:24 sokdesk ModemManager[1300]:   [sleep-monitor] system is about to suspend
Jan 18 05:43:24 sokdesk systemd[1]: Reached target Sleep.
Jan 18 05:43:24 sokdesk systemd[1]: Starting Record successful boot for GRUB...
Jan 18 05:43:24 sokdesk systemd[1]: Starting Suspend...
Jan 18 05:43:24 sokdesk systemd-sleep[2574]: Suspending system...
Jan 18 05:43:24 sokdesk kernel: [ 1217.283955] PM: suspend entry (s2idle)

When this happens, the remote desktop and SSH connections to the server get disconnected. To get back to the server, I had to restart the server.

The error is fixed by running the command

systemctl mask sleep.target suspend.target hibernate.target hybrid-sleep.target