Last week I had a fight with my odroid HC1 to get it booting a centos-kernel and userland rootfs.
Finally I have some results to share; its not ready jet 
however
here are my rough notes
great work!
it seems i have something to do in my next free time… tnx! i really hope to see soon ns7 on my hc1 
Interesting readings. Would it be possible for the ARM team to list all known devices that are compatible with this effort? I need to do some catching up on this new world order 
Thanks.
Note (as said) it’s not completely ready, I have a hunch a driver for the voltage regulator is still missing.
BTW NS 7.5 runs good on a pristine vendor (hardkernel) kernel extracted from Arch Linux Arm packages. Never got SELinux to work though and that is a kind of a big deal because this makes it impossible to create arm images with SELinux set to (NS Default) permissive. 
And it tuns out this is possible now 
Well, the standard answer is : If you get Centos up and running NS will work to.
So you have to rely on the success stories of the community 
EDIT:
There will be more news about the nethserver-arm effort coming soon.
Here it is: ARM development: next steps
So if I purchase a Raspberry Pi 3B+ I can experiment?
Yes, that is a very safe and well supported choice.
I can recommend to purchase the commonly offerted power supply too - and as always - try not to be to greedy at the choice of SD card. (a card => 8GB with a Application Performance Class rating (A1/A2) is highly recommended due to its random write/read performance)
See:
https://wiki.centos.org/SpecialInterestGroup/AltArch/armhfp
For armv7 boards support.
You can join the centos-arm list or at least follow the archives for work on other boards:
https://lists.centos.org/mailman/listinfo/arm-dev
Karanbir (principal Centos developer) started the effort back in 7/14. By this time, we had ~1.5 years with Fedora (18) on arm:
http://lists.fedoraproject.org/pipermail/arm/2013-February/005314.html
And Bobic had been working with his Redsleeve-6 userspace on armv5 RPi and Kirkwood for some time. That F18 uboot made it possible for me to get RSEL6 working on Cubieboards and others to jump on the bandwagon.
So there are a lot of years of a small active community developing and testing Fedora/Centos on Arm that is making Mark’s and other’s work possible.
Thing to think about in getting a board is:
What are your goals for using Neth on arm?
If it is beyond playing, you really need to think what storage media you will use. You will see me very concerned on sata boot support, and performance of sata. Is it native? (Some Allwinner like Cubieboards, Linkspire, and some BananaPi and some Wandboards), or is it USB/sata bridge (which might not support /boot partition). The Odroid HC1 is, I believe usb/sata bridge, but it seems that now the uboot is supporting direct booting?
Oh, and will it fit in my budget!
Great work Mark, and I am now expanding my board selection process for my mailserver to consider the odroid HC1.
I am getting interested in this board for my production mailserver. I found:
as a source of specs on the board.
I see that the barrel power plug is a different size than I have for my Cubieboards (and BananaPi M2-Ultra), so I will have to get the power cable as well. (5.5mm vs 4mm)
Is there any US distributor that sells the board with just the power cable?
Will 3A (Anker 40W 5-port power supply) be enough with a 1A sata drive?
I have a couple Ankers here and DON’T put a smart device in or you only get 1A from the other ports! If no smart USB charging, the max 3A to a port, of course it is only 8A total…
I am looking at their newer 60W unit.
Also the serial UART header. Does it provide Rx/Tx/Grd for attaching a TTL/USB adapter (~$2 each) for getting console via screen?
e.g. “screen /dev/ttyUSB0 115200”
Is there a hole in the case for running the serial wires through or do I have to drill a hole? 
Thanks
Sorry have not tried this, my preferd setup is to keep the kernel on the SD-Card.
The PSU of the vendor is rated 4A, and this SBC is known for quite high inrush currents and steep powerdraw rises. The later is understandable as they can go from idle to full cpu usage in a split second.
They provide a UART/USB adapter, which they (of course) recommend–they say their signal levels are lower than TTL (don’t recall if they’re at 3.3v or 1.8v, but in any event not 5v). It’s more than $2, but still not too bad.
You can order directly from hardkernel, and they ship pretty quickly (it’s what I did). They do sell the power cord separately, or they also sell a compatible PSU. Another option would be ameridroid.com, but I’m not sure if they sell just the cable.
Could someone please try this out? It will be of value to someone considering this board. IMHO.
Their UART/USB is interesting and not cheap ($9), but looks easy enough to use. Would have work on the clear cover to make a connected hle to one of the other openings to pass the cable connector through before covering everything up. But manageable .
Their PSU is cheap enough not to sweat it ‘Just’ another thing plugged into my Tripplite UPS.
Definitely considering this. Hopefully you all will move this along so that when I get back from IETF/IEEE 802 mid-Nov, I could order then and get it working!
Hi, I own a HC1, it’s wonderful
The best distro for running it is ARMBIAN, which, as you might immediately get, is based on debian (although they also made an ubuntu based flavour) and features some ready prepackaged appliances like openmediavault. Definitely not the richness of NethServer, but quite much for such a niche product.
My suggestion is: have a look at which customizations they put in place, and try to port them back to centos. On armbian HW works 100% and speed is super! 
Anyway, even if the HC1 is fantastic for power and space efficiency (the stackable option is also fun), in my opinion it has some setbacks:
Plus, unless you drop it in some datacenter, forget about using it as a mail server, as the absence of control for your dns PTR records on soho connections will be a clear show stopper.
Why? Use the serial console.
yes Armbian is a fantastic project for arm enthusiasts and I often look at their progress getting the boards to run on a mainline kernel. And centos runs fine on their kernels expect (the last time i tried) SELinux policies of centos won’t play along. (and you have to update them manually…)
As @danb35 said i prefer to use a serial console and free up the memory used by the gpu. Do not know the bennefits on a XU4; on a C2 you gain about 250 MB of usable RAM. 
You may use the smarthost, sending you mail from IP your domian is hosted and you have a say in the control over the DNS records.
Today, I did a Centos install simply to my new Odroid-HC1. The image is still a little ‘testy’, but is available from the Centos-arm image server.
Plus is is easy to put the swap and rootfs partitions on the sata drive.
As a single drive solution, this is a great unit.
I am working on updating my Centos install page to include instructions for the HC1.
As for using it as a mail server at home, if you have AT&T Internet, you can get a block of static IPv4 addresses (no IPv6) and there is a magic page where you can request the rDNS PTR record. I think it is $15/mo for a /28 block (5 usable addresses).
Nice to read you are up and going again!
For those who are interested in the experimental / testing-image made by the centos maintainer / developer here the link:
https://armv7.dev.centos.org/repos/images/
Looking forward to the results, please ping me on it!