I would like to know how to check gnome desktop manager version on my Redhat 7 Linux server/desktop?
Redhat / CentOS / AlmaLinux
Sync an accurate time using ntpdate on RHEL7 Linux server
To sync a correct time on your Redhat server with a NTP publicly available time servers first you need to install ntpdate
package:
[root@rhel7 ~]# yum install ntpdate
To check your current time use date
command:
[root@rhel7 ~]# date Thu Sep 4 17:20:42 WST 2014
Next, we can use pool.ntp.org
timeserver to synchronize our time. This is be done with ntpdate
command:
[root@rhel7 ~]# ntpdate pool.ntp.org 11 Dec 06:08:13 ntpdate[2225]: step time server 173.230.144.109 offset 8426822.014383 sec
Configure firewall to enable NTP port 123 on RHEL7 Linux
Once you configure NTPD service on your RHEL7 linux you will need to allow traffic through the firewall on port 123. Te following linux command will enable all public traffic on UDP port 123:
# firewall-cmd --zone=public --add-port=123/udp --permanent success
Update GRUB2 menu timeout on RHEL 7 Linux
The default settings for the GRUB2 timeout menu selection during the system boot is 5 seconds. To change this value open /etc/default/grub
grub default config file. The content of the file looks similar the the one shown below:
GRUB_TIMEOUT=5 GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)" GRUB_DEFAULT=saved GRUB_DISABLE_SUBMENU=true GRUB_TERMINAL_OUTPUT="console" GRUB_CMDLINE_LINUX="rd.lvm.lv=rhel/root crashkernel=auto \ rd.lvm.lv=rhel/swap vconsole.font=latarcyrheb-sun16 vconsole.keymap=us rhgb quiet" GRUB_DISABLE_RECOVERY="true"
Persistent/Automatic after reboot kernel module loading on CentOS/Redhat Linux
This config will describe a procedure on how to persistently load kernel modules during a boot time on CentOS or Redhat Linux system. In the below commands will use nf_conntrack_pptp
as a sample module. Replace the name of this module with a module name you wish to load.
First, create a script within /etc/sysconfig/modules/
directory with a file extension modules
. Where the name of the script can be any name of your choice. In our case the script will be called nf_conntrack_pptp.modules
. Enter a following code into your new nf_conntrack_pptp.modules
script while replacing the name of the module with the one you wish to load:
#!/bin/sh exec /sbin/modprobe nf_conntrack_pptp >/dev/null 2>&1
Failed to issue method call: Unit .service failed to load – RHEL7 Linux error
Symptom
When trying to start a service with service
or systemctl
commands on the Redhat 7 Linux system the following error message can appear on the screen:
Failed to issue method call: Unit service_name.service failed to load: No such file or directory.
How to reset the root password in RHEL7/CentOS7/Scientific Linux 7- based systems
Objective
Resetting the root password in RHEL7/CentOS7/Scientific Linux 7
Requirements
RHEL7 / CentOS7 / Scientific Linux 7
Difficulty
MODERATE
Instructions
Things have changed in the RHEL7 world and so has the preferred way of resetting the root password. Although the old way of interrupting the boot process (init=/bin/bash) still works, it is no longer bulletproof and recommended.
‘Systemd’ uses ‘rd.break’ to interrupt the boot. Let’s have a quick walk through the whole procedure.
Configuring VNC Server Access on a Redhat Linux
Most of the time as a Linux system administrator you are managing your servers over the network. It is very rare that you will need to have a physical access to any of your managed servers. In most cases all you need is to SSH remotely to do your administration tasks. In this article we will configure a GUI alternative to a remote access to your RHEL server, which is VNC. VNC allows you to open a remote GUI session to your server and thus providing you with a full graphical interface accessible from any remote location.
In this tutorial you will learn:
- How to install required VNC packages
- How to setup and start the VNC server on RHEL
- How to connect to a graphical session remotely
- How to run graphical programs in the xterm session