centos

Check Reboot After Updates

July 16, 2021

Here’s the command to check if the system needs a reboot after running yum update.

Must be root or run it sudo.

$ needs-restarting -r ; echo $?
Core libraries or services have been updated:
  openssl-libs -> 1:1.0.2k-21.el7_9
  kernel -> 3.10.0-1160.31.1.el7
  dbus -> 1:1.10.24-15.el7
  linux-firmware -> 20200421-80.git78c0348.el7_9
  glibc -> 2.17-324.el7_9
  systemd -> 219-78.el7_9.3
 
Reboot is required to ensure that your system benefits from these updates.
 
More information:
https://access.redhat.com/solutions/27943
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In this instance, it requires a reboot due to a new kernel.

Install OpenJDK 8

January 31, 2021

Here’s the installation instructions for OpenJDK 8.

For Fedora, Redhat and Oracle Linux.

yum install java-1.8.0-openjdk

For Debian and Ubuntu.

apt-get install openjdk-8-jre

To see if the packages (symbolic links) are there, they can be found in /etc/alternatives/, at least in Redhat 7.

ls -l /etc/alternatives/

HTTPD on Redhat & Centos

December 4, 2020

Here are the commands to start, stop, enable and get the status of Apache on RHEL and CentOS.

systemctl enable httpd  # enable on bootup
systemctl status httpd  # get status
systemctl start httpd   # start
systemctl stop httpd    # stop
systemctl restart httpd # restart