Best Available Open-source Operating System for Zimbra Collaboration OSE | Zimbra

Alert! This article is written for Zimbra OSE users. As of December 2023, Synacor will no longer be providing support for Zimbra OSE. You might want to consider trying out Carbonio Community Edition – Zextras’s free and open-source email and collaboration platform.

For additional guidance, check out our community articles detailing the process of migrating from your current platform to Carbonio CE.

Selecting the proper operating system for your server is as important as defining other key requirements (i.e hardware). Migrating or updating an operational server’s operating system is not as easy/effortless as we may expect. Therefore, selecting a stable, robust, secure operating system is one of the key prerequisites. If you are used to a specific operating system and you want to evaluate your choice or you need to select an OS for your future server, this article will help you to think in the right direction.

It Is Not As Simple As It Was

Don’t worry we will discuss this issue in detail and in a simple manner so that you can understand the facts:

Now let’s take a look at some key factors of OS selection:

  • Life Cycle & Support of an OS
  • Price of subscriptions
  • Level of expertise needed to operate
  • Security, Vulnerability, and Robustness
  • Hardware resources required to run the OS
  • Hardware resources required to run the OS

Currently, Zimbra OSE supports five Linux platforms. They are:

  • Red Hat Enterprise
  • Oracle Linux
  • Ubuntu
  • CentOS
  • Rocky Linux

Among these five, only the first three are included in our discussion. Let me tell you why

In December 2020, Red Hat announced that they will no longer release any stable version of CentOS. Currently running CentOS 7 & 8 will be the end of life after May 2024. Therefore, in spite of being one of the most loved production-ready server OS, we have to leave CentOS out of this equation. Actually, we have an article on CentOS, click CentOS is dying: What’s next? to check out the article.

Rocky Linux is the outcome of enormous effort from the original founders of CentOS. They also announced that it will be an effort to achieve the original goals of CentOS. As a result, it is named after CentOS co-founder Rocky McGaugh and started its journey. It has the potential of becoming a true alternative to CentOS. With the number of its growing community, Zimbra OSE has included Rocky Linux as its supported platform but as a BETA version for now. Hence, we are excluding Rocky Linux from the discussion.

Therefore, we have only three options left.

  • Red Hat
  • Oracle Linux
  • Ubuntu

*** Among these three platforms some earlier versions are deprecated.

Life Cycle & Support Of An OS

RHEL 8 was released in May 2019 and will provide active support and security support respectively till May 2024 & 2029. But to avail of that support, you have to purchase a subscription. Here, the support means all updates, upgrades, and patches.

Oracle Linux 8 was released in July 2019 and will provide support till 2029. Just like RHEL, you can avail yourself of the support by obtaining a basic or premium subscription.

Ubuntu 20.04 LTS released in 2020 and will provide hardware, and maintenance updates till 2025. It will also provide extended security maintenance till 2030. You can take an advanced support subscription but you will still get updates, and patches without any paid subscription.

Therefore, if you like to get professional help you can choose between RHEL or Oracle Linux otherwise, you can opt-in for Ubuntu.

Pricing Of Subscriptions

Among these three platforms (RHEL, Oracle Linux & Ubuntu) Red hat has higher pricing models. Though Ubuntu is a free-cost operating system you can get their advanced support by purchasing their commercial support.

Level of Expertise Needed To Operate

All three mentioned operating systems are easy to install. You can deploy and manage them in an easy and fast way.

But there is a catch. RHEL is not available for free download just like other open-source Linux distros. You have to open an account in the Red Hat portal to download RHEL.

Whereas, you can download Oracle Linux for free. You can also download Ubuntu from their official webpage.

In RHEL & Oracle Linux, you have to use dnf/rpm-based package manager and in Ubuntu, you will get the apt/dpkg package manager.

Other than this their regular operations are very much similar to each other.

Security, Vulnerability & Robustness

RHEL, Oracle Linux & Ubuntu are enterprise-grade server OS. They manage their update, upgrade, and security patches differently (Through their subscription portal and community channel). But most importantly they provide them in a timely manner to keep their users safe.

On one hand, RHEL and Oracle Linux use SELinux and on the other hand, Ubuntu uses AppArmor to strengthen its security.

Hardware Resources Required For The OS

Ubuntu is the OS among these three that can run on a lower specification server. But you shall calculate your hardware requirement considering not only your base operating system but also the application you are going to deploy in it.

Still thinking, let’s extract the essence from our discussion to get to a conclusion:

  • All three OS are stable and robust.
  • All need the same level of expertise to operate.
  • Do you need expert support or community-based support would do for you?

I think you got the answer.

Last But Not The Least

If we have any updates about more supported platforms in Zimbra OSE, we will be happy to write about them here in the community.

Before we close this discussion, if you have any existing server on CentOS that has reached its EOL, you may check How To Maintain Your Zimbra Servers After Soon-coming CentOS End-of-life to get a heads up.

That’s all for today.

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Are you planning to release Zdocs server for Ubuntu20/RHEL8? If so, when will it be? A rough estimate will be fine. Regards.

Hi @funifuni, there is no specific plan right now; however, it is an ongoing decision and may change soon. In that case, I will update you.


Oracle 8 can also be installed over top a centos 8 server with a simple shell script provided by them ( and in many cases doesn't require a reboot to your running server. That comes in handy with some cloud providers that don't provide Oracle 8 as an option when you want RHEL 8 but don't have a budget for a license. Should you later decide that you want OS technical support for it, it's available and doesn't require you choose a free vs paid version at time of installation like centos/RHEL did for many years. Upgrades track almost as fast as RHEL 8 vs the delay we saw in centos. The 10 year life-cycles are an advantage for something with as many moving parts as zimbra. When coupled with virtualization, the hardware capability can be updated transparently during this 10 year cycle as your requirements dictate to maximize zimbra availability.

Md. Shariful Islam

Hi, Thanks for your insight. It was a nice workaround that you mentioned. After going through and, I think we need more time if it will be a stable workaround or not. Therefore, for the time being, we should set our choosing factors based on each OS's own evaluation. Thanks


" Ubuntu uses AppArmor" : but the official Zimbra installation documentation suggests disabling AppArmor ...

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