When managing a Linux cloud server, it is essential to develop the habit of regularly updating the operating system kernel and other software packages. This article introduces methods for updating various versions of the Linux operating system.

Before updating the system, especially if it has not been updated for a long time, it is crucial to back up your data to prevent system damage and ensure usability. Additionally, it is advisable to stop running applications such as websites and databases. System updates also require a certain amount of disk space. If your disk is full, please clear the disk space or consider upgrading it. It is recommended to reserve at least 500MB of space for the upgrade.

CentOS

Install the EPEL repository to provide additional software sources for the system:

yum install epel-release -y

Install updates and reboot the operating system:

yum update -y
reboot

Note: CentOS does not support major version updates, such as upgrading directly from CentOS 6 to CentOS 7.

Ubuntu/Debian

Fetch available updates:

apt update

Install updates and reboot the operating system:

apt upgrade
reboot

Clean up unnecessary software packages:

apt autoremove --purge

Upgrade across versions: (e.g., upgrading from Ubuntu 18.04 to Ubuntu 20.04)

do-release-upgrade

Fedora

Check for available updates:

dnf check-update

Install updates and reboot the operating system:

dnf upgrade
reboot

FreeBSD

Fetch available updates:

freebsd-update fetch

Install updates and reboot the operating system:

freebsd-update install
reboot

System updates can take a varying amount of time, from a few minutes to several hours, depending on download speeds and the number of software packages. Do not interrupt the system update process, as it could damage the operating system and render it unusable.

Updating a Linux cloud server is a relatively straightforward task but can be easily overlooked. Regularly updating the operating system is vital for patching system vulnerabilities and enhancing system security.