It’s possible, but you should be able to see it quite easily. In my case, the CPU utilization was very low, so the same test should also not be CPU-bottlenecked on your system.

I’m seeing very similar speeds on my two-HDD RAID1. The computer has an AMD 8500G CPU but the load from ZFS is minimal. Reading / writing a 50GB /dev/urandom file (larger than the cache) gives me:

• 169 MB/s write
• 254 MB/s read

What’s your setup?

With version 2.3 (currently in RC), ZFS will at least support RAIDZ expansion. That should already help a lot for a NAS usecase.

We use Alma Linux at work and it’s fine, I suppose. I see two main reasons why you’d choose an EL linux distro:

1. You have (professional) software that officially supports it. RHEL’s release model makes it an attractive target for proprietary software and many vendors choose to support it.
2. You need/want very long support cycles. You can run 10-year-old software even though you probably shouldn’t.

Apart from those, it’s a competent distro, Red Hat know what they’re doing. If you want the equivalent to an Ubuntu LTS / Debian in the Fedora world, it get’s the job done. I quite like their approach of keeping the core OS stable while updating drivers, tools, and compilers (e.g., the kernel version number has very little meaning in RHEL).

Is the experience very different from Fedora?

Yes. the age of the core packages is very noticeable. The number of fully supported packages is also very small and you need to go to EPEL very quickly (at which point you’re no longer getting enterprise support…). On the plus side, it’s much more stable than Fedora in my experience.

Edit: My main recommendation for a stable distro would probably be Debian unless one of the above points applies.