memtest+ redhat 7 grub menu available

Installation of Memtest+ RAM memory test tool on Redhat 7 Linux

Installation of Memtest+ RAM memory test tool on Redhat 7 Linux

Memtest is a quite handy tool when troubleshooting hardware problem and specifically problems related to Random Access Memory (RAM). After installation the memtest+ tool will become available among other boot options. To install memtest+ on RHEL 7 Linux server execute the following linux command:

# yum install memtest86+
Running transaction
  Installing : memtest86+-4.20-12.el7.x86_64      1/1 
  Verifying  : memtest86+-4.20-12.el7.x86_64      1/1 

  memtest86+.x86_64 0:4.20-12.el7

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Monitor CPU temperature on Redhat 7 Linux

How to monitor a CPU temperature on Redhat 7 Linux system

Here is a short config to show you how to display and monitor CPU temperature on a Linux system running Redhat 7 Linux. First we need to install lm_sensors:

# yum install lm_sensors

Next, use sensors command to display CPU temperature:

$ sensors | grep Core
Core 0:         +43.0°C  (high = +86.0°C, crit = +100.0°C)
Core 1:         +43.0°C  (high = +86.0°C, crit = +100.0°C)

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How to install, manage, start and autostart ssh service on RHEL 7 Linux

systemctl command is used on RedHat 7 linux to manage services system wide. It allows administrators to manage ssh service to start, restart, stop or enable autoload after system startup.

In install ssh service on your RHEL 7 linux run a following linux command:

# yum install openssh

By defalt SSH service or to be more precise sshd ( daemon ) is disabled. Once the opensshd package installed, you can check the status of SSHD service by using the below command:

# systemctl status sshd
sshd.service - OpenSSH server daemon
   Loaded: loaded (/usr/lib/systemd/system/sshd.service; disabled)
   Active: inactive (dead)

To start ssh daemon (sshd) on RHEL 7 run:

systemctl start sshd

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Configure network interface as DHCP client on RHEL7 Linux

In this config we are going to configure a network interface to receive an IP configuration settings from DHCP server. First get the name of the network interface you would like to set as DHCP client. To do this you can run command:

# ip addr show
2: enp0s3:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 08:00:27:15:38:b7 brd ff:ff:ff:ff:ff:ff
       valid_lft forever preferred_lft forever
    inet6 fe80::a00:27ff:fe15:38b7/64 scope link 
       valid_lft forever preferred_lft forever

Once we have located a name of the network interface in question open a corresponding configuration file. So as an example, for network interface epn0s3 vi will edit a /etc/sysconfig/network-scripts/ifcfg-enp0s3. Open this file and enter the minimum configuration settings in order to make this network interface act as a DHCP client:


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How to change a static hostname on RHEL7 linux with hostnamectl

Instead of changing a hostname on your Redhat 7 server manually by editing /etc/hostname you may preferably use a dedicated command hostnamectl to do this job. By default when no other options are supplied the hostnamectl command will display basic information including static hostname:

[root@rhel7 ~]# hostnamectl 
   Static hostname: rhel7
         Icon name: computer
           Chassis: n/a
        Machine ID: 75387b56d72b44b380810499805ec28a
           Boot ID: 6ad251d0e12a10e3af1894eae5fe5cb6
    Virtualization: oracle
  Operating System: Red Hat Enterprise Linux Server 7.0 (Maipo)
       CPE OS Name: cpe:/o:redhat:enterprise_linux:7.0:GA:server
            Kernel: Linux 3.10.0-123.el7.x86_64
      Architecture: x86_64

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How to list all available locales on RHEL7 Linux

The following linux command will list all available locales currently available on the Redhat 7 system:

[root@rhel7 ~]# localectl list-locales

The list of all available locales on your system my be quite long so use grep command to narrow down your search. Bellow command will display for example all German available locales:

[root@rhel7 ~]# localectl list-locales | grep ^de

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How to reset the root password in RHEL7/CentOS7/Scientific Linux 7- based systems


Resetting the root password in RHEL7/CentOS7/Scientific Linux 7


RHEL7 / CentOS7 / Scientific Linux 7




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.

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VNC connection to RHEL

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

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