Assembling your own NAS can have a number of benefits over buying pre-built enclosures. Besides customizing the hardware to your liking, you also get to pick between quite a few operating systems that bring their own set of pros and cons to the table.

If you're even remotely into NAS or home servers, you may have come across TrueNAS Core and Scale. Despite sounding rather similar, the two have their fair share of differences and there are plenty of reasons to pick one over the other. In this article, we’ll pit the two against each other to help you pick the perfect OS for the NAS setup of your dreams.

Architecture and future updates

Winner: TrueNAS Scale

Based on FreeBSD, TrueNAS Core is far older than its sibling and has been fine-tuned over the years. While TrueNAS Core won’t be discontinued anytime soon, updates to the OS have slowed down for now. iXsystems, the company behind these incredible operating systems, only intends to deploy maintenance updates for TrueNAS Core and there aren’t any new features planned for the OS.

As of writing, iX also doesn’t plan to release a FreeBSD 14.0 version of Core, so we’re stuck on the older version for the time being. Plus, the firm will also drop support for Core plugins by 2025, meaning you’ll need to move them over to a jail (more on that later) if you wish to continue using TrueNAS Core with your favorite plugins.

Meanwhile, TrueNAS Scale is the new Debian-based OS that packs more advanced features than Core. It’s also the variant that iXsystems intends to divert all their attention to in the near future. So, if you want a NAS OS that will get plenty of updates, TrueNAS Scale is the better alternative.

Clustering

Winner: Neither

For the uninitiated, clustering is a facility that lets you combine the storage and processing capabilities of three or more TrueNAS Scale nodes, effectively using them as a single unified setup. Or at least, that used to be the case until a few months ago.

Had I written the article a year ago, I would’ve crowned TrueNAS Scale the victor in this category, as the free, non-Enterprise version of TrueNAS Core just doesn’t support this functionality. Unfortunately, the Gluster filesystem used in clustering has been deprecated from the latest version of TrueNAS Scale, so there’s no way to set up clusters on the OS as of writing.

Virtualization and containers

Winner: TrueNAS Scale

Besides file sharing, data storage, disk backup, and other everyday NAS-related tasks, TrueNAS Core and Scale have plenty of use cases thanks to virtualization. However, there’s a major difference in the hypervisor and containerization methods utilized by both. Whereas TrueNAS Core uses the older FreeBSD Bhyve (pronounced as beehive) and runs jails via IOCage, TrueNAS Scale has a KVM-based hypervisor and, as such, supports both Docker and Kubernetes containers.

For the average user, there shouldn’t be a lot of performance difference between Bhyve and KVM, though the former is usually a little faster and has better stability. Meanwhile, the reverse is true for jails versus dockers. Although the jails created in TrueNAS Core can be more secure than your average docker container, the latter tends to have better scaling provisions when deploying multiple containers. Another plus point of Docker and Kubernetes containers is that they are compatible with a host of apps and services, while Core’s jails just aren’t all that popular in the developer community in 2024. With KVM and Docker growing more popular by the second, I’d suggest picking up TrueNAS Scale if you want to stay up to date with the newest hypervisor and containerization platforms.

Network shares

Winner: TrueNAS Core

If we’re going by the current file-sharing protocols available on the TrueNAS operating systems, then Core is far ahead of Scale. While Scale is only compatible with SMB, iSCSI, and NFS shares, Core supports WebDAV and Apple File Protocol in addition to the three protocols.

Unfortunately, the Apple File Protocol will be deprecated from Core in the near future, leaving WebDAV the only network service exclusive to TrueNAS Core.

Performance and stability

Winner: TrueNAS Scale

Finally, it’s time to compare the performance of TrueNAS Core and Scale. Unfortunately, it’s not quite an apples-to-apples comparison, because both tools are made for different audiences and specifications. For those who are rocking an older system, then TrueNAS Core will definitely feel a lot faster, especially if you want to work with jails and VMs. Meanwhile, TrueNAS Scale is meant for modern hardware, so you'll need decent specs (at least, by NAS standards) if you want the newer OS to feel snappy and responsive.

Nevertheless, I decided to flash the latest versions of TrueNAS Core and Scale on the same machine to grab some performance metrics for both. For reference, I installed TrueNAS Scale first and ran all the tests before switching to its older sibling. Since I could only access a Windows system besides my makeshift Ryzen 5 1600 NAS, I used CrystalDiskMark to run sequential and random 4K read and write tests on SMB shares and iSCSI local drives.

And well, the results were pretty much what you'd expect. In nearly every case besides Sequential Reads, the TrueNAS Scale configuration outperformed Core’s SMB and iSCSI shares. That said, if we remove virtualization tasks or the read/write statistics, both Scale and Core are quite responsive, and I haven't experienced weird bugs on either TrueNAS offering. But when it comes to stability, TrueNAS Core has a slight advantage, largely due to the fact that it’s more mature and has been fine-tuned for years.

TrueNAS Scale vs Core: The new kid on the block or the mature champ?

Get Core for the stability and Scale for the features

Despite their differences, TrueNAS Core and Scale have plenty of similarities. Both support the ZFS file system and are compatible with Stripe, Mirror, and RAID arrays (though only Scale supports declustered RAID).

If you're new to the world of NAS and aren’t sure of where to start, the TrueNAS Scale is easily the better alternative. Besides being updated with newer features at frequent intervals, Scale has better virtualization and container support. Plus, iXsystems has improved the OS’ functionality and stability in the last two years, and personally, I find its UI a lot easier to navigate than its older sibling.

But that doesn’t mean Core is useless or outdated. Sure, it’s in its maintenance phase, and you won’t see any groundbreaking features added to the OS for a while. But for a simple file-sharing NAS built on decade-old hardware, you won’t encounter any issues with TrueNAS Core.