Elastic Compute Service:Overview of the operating system lifecycle

Phases of the operating system lifecycle

After an operating system is released, it goes through the following key lifecycle phases based on the support provided by the vendor:

1. Mainstream Support (MS) phase: The product vendor provides comprehensive support and services, including updates, vulnerability fixes, and technical support. This phase typically lasts for a long time, often until the product is no longer sold.

2. Extended Life Support (ELS) phase: The availability of this phase depends on the operating system and market demand. In this phase, the vendor typically provides very limited support, which is generally restricted to critical security updates and vulnerability fixes. New feature updates are no longer provided. Support in this phase is usually a paid service or is provided only to specific customers.

3. EOL phase: In the EOL phase, the vendor no longer provides any form of support for the operating system, including security updates and technical support. This marks the official retirement of the operating system.

An inevitable result of technological progress and market demand

The operating system lifecycle is primarily driven by technological advancements and market changes. As technology iterates, older versions of operating systems may not be able to fully use the latest hardware resources. Security threats are also constantly evolving, exposing older operating systems to higher risks. Continuing to support old operating systems is costly and inefficient for vendors, who prefer to focus their resources on developing more advanced products. Market demand also drives vendors to update their operating systems because older systems cannot meet growing user needs for new features, performance, and security. By setting clear lifecycles, vendors can encourage users to upgrade to the latest versions in a timely manner to obtain better performance and security protection.

Impacts of different operating system maintenance phases on your business

MS phase

The system vendor provides comprehensive support and services, including updates, vulnerability fixes, and technical support. You should follow the vulnerability patches released by the vendor and apply them in a timely manner to ensure business security and stability at the operating system layer.

ELS phase

When an operating system is in the ELS phase before it reaches EOL, the operating system vendor typically provides a certain degree of security updates and technical support. However, compared with the MS phase, some potential risks still exist:

1. Limited security updates: Compared with the MS phase, the number of security patches provided during the ELS phase may be reduced, and the release frequency may also decrease. This reduces the system's ability to defend against the latest threats.

2. Stagnation of feature updates: During this period, the development of new features for the operating system essentially stops. Support is limited to maintaining existing features and fixing critical errors. Therefore, you may not benefit from the latest technologies and user experience improvements.

3. Increased costs: To obtain additional support services, your organization may need to pay extra fees. This can be a significant expense, especially for commercial operating systems.

4. Migration pressure: As the ELS period approaches its end, organizations face increasing pressure to plan and execute the migration to a newer operating system version. This process often involves a significant investment of time and resources.

In summary, although the ELS period can provide some buffer time, the risks of the EOL phase are unavoidable. Timely planning and implementation of a migration to a more modern and supported operating system version is a key measure to reduce these risks. At the same time, strengthening existing security management measures can also alleviate the impact of losing official support to some extent.

EOL phase

After the operating system of an Elastic Compute Service (ECS) instance reaches EOL, the vendor no longer provides support, such as support for new software, new hardware, error fixes, or security fixes. If you use an ECS instance whose operating system has reached EOL, you will face many serious problems:

• Security issues: An EOL operating system no longer receives security updates or patches, making the system vulnerable to malicious attacks and hacking.

• Compatibility issues: An EOL operating system may be incompatible with new hardware or software, causing the system to crash or fail to run as expected.

• Compliance issues: Some countries, industries, or organizations require compliance with specific security and compliance standards. Using an EOL operating system may violate these requirements.

• Reliability issues: An EOL operating system may experience errors that lead to system instability, data loss, or file corruption. This in turn affects your business operations and data integrity.

• Maintenance costs: An EOL operating system no longer receives technical support. Therefore, you need to spend more time and money to maintain and manage the system.

EOL solutions

Event response and risk assessment

You need to respond to the EOL event of an operating system based on your current business situation. For example, if the corresponding service is about to be taken offline, you can ignore this event. For new services, we recommend that you do not use an image of an EOL operating system to create new ECS instances. You can choose an operating system that is compatible with your existing services and is in the MS phase to host your services. For existing services, you can choose a short-term transition plan or a long-term solution as needed.

Short-term transition plan: Subscribe to ELS

Extended support is a short-term compromise provided by system vendors who consider the migration difficulties for users. It reduces the vendor's development investment in that system version and guides users to upgrade or migrate their systems. If you cannot change the operating system to a newer version in the short term, you can subscribe to extended support from the original vendor or a third party as a transitional solution to receive continuous updates and fixes for a period of time.

However, not all operating systems offer ELS, and subscribing to ELS is not always the best option. You should evaluate whether to subscribe to ELS based on the current status of your services deployed on ECS instances. Alternatively, you can choose to immediately upgrade or replace the current operating system to achieve long-term stability for your services.

Long-term solution: Operating system migration and upgradation

ELS can only relieve the pressure of a system replacement or upgrade in the short term. In the long term, we recommend that you plan to replace or upgrade your operating system to one that is in its MS phase. The complete implementation process is roughly divided into the following five phases. For the data backup, compatibility verification, and acceptance and optimization phases, you must design your own plans based on your actual business architecture and scenarios. The remaining steps are described in detail below.

Understand migration solutions

Before you select a migration solution, you need to understand the upgrade or operating system migration and replacement solutions that Alibaba Cloud provides. The following three main solutions are available:

Solution 1: Redeploy the environment (purchase new instances)

This solution involves creating new ECS instances to replace the original environment.

• If your environment is a container cluster, you can perform a rolling replacement to gradually replace the nodes in the cluster without interrupting your services.

• If your environment is an ECS environment, you may need to plan a downtime window. This depends on whether your business system architecture has primary/secondary backup measures in place. If the legacy ECS instances can be released as your business iterates, you can select an operating system that is in its MS phase when you create new ECS instances.

Solution 2: Replace the system disk (replace the operating system)

This solution involves replacing the system disk of the original ECS instance. The ECS instance restarts when its system disk is being replaced. During the restart, the instance cannot provide services.

Solution 3: In-place upgrade or transformation

This solution involves upgrading or transforming the operating system version within the instance without changing the system disk of the ECS instance. For example, you can perform an in-place upgrade from Alibaba Cloud Linux 2 to Alibaba Cloud Linux 3, or an in-place transformation from CentOS 7 to Alibaba Cloud Linux 3. The ECS instance restarts during the in-place upgrade or transformation. During the restart, the instance cannot provide services.

Lifecycle and EOL/ELS solutions for different operating systems

• For more information about the lifecycle and EOL solutions for CentOS, see CentOS operating systems.

• For more information about the lifecycle of Alibaba Cloud Linux and the solutions for risks when it enters the ELS phase, see Alibaba Cloud Linux operating systems.

• For more information about the lifecycle of Ubuntu and the solutions for risks when it enters the ELS phase, see Ubuntu operating systems.

• For more information about the lifecycle of Red Hat Enterprise Linux and the solutions for risks when it enters the ELS phase, see Red Hat Enterprise Linux operating systems.

• For more information about the lifecycle of Windows Server and the solutions for risks when it enters the end-of-maintenance phase, see Windows Server operating systems.

• For more information about the lifecycles of Debian, Anolis OS, FreeBSD, OpenSUSE, SUSE Linux, Fedora, Rocky Linux, AlmaLinux, and Fedora CoreOS, see Other operating systems.