Uly.me

cloud engineer

Check Reboot After Updates

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.

Set Timezone Permanently

It’s recommended to set the clock to UTC. In rare occasions, local time may be needed.

Here’s how to set your server’s timezone permanently.

Check the date first.

date

Backup localtime. Set it to US Eastern Time.

mv /etc/localtime /etc/localtime.backup
ln -s /usr/share/zoneinfo/America/New_York /etc/localtime

Backup clock. Set it to US Eastern Time.

cp -p /etc/sysconfig/clock /etc/sysconfig/clock.backup 
> /etc/sysconfig/clock
echo ZONE=\"America/New_York\" > /etc/sysconfig/clock

Run the date again to validate.

date

Install OpenJDK 8

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/