How I installed TrueNAS on my new ASUSTOR NAS

A common question I get asked whenever my ASUSTOR NAS makes an appearance is: "but can it do ZFS?"

I'm still trying to convince them to add it to ADM alongside EXT4 and Btrfs support, but until that time, the 2nd best option is to just run another OS on the NAS! This is now permitted, but you won't get technical support from ASUSTOR for other OSes.

Some people (myself included) like buying hardware and... doing what we want with it! And for computer hardware, that often involves installing whatever OS and software we want to do the things we want to do. Pretty crazy, coming from a guy who uses a Mac, right?

ASUSTOR Flashstor 12 - front

The Flashstor 12 just came out, and ASUSTOR sent me one for testing. It has an Intel N5105 CPU in it, and the system is configured as a typical mini PC—just with twelve NVMe slots and 10 Gbps Ethernet. It even has HDMI, USB, and SPDIF optical audio, so it's almost purpose-built to be a quiet media desktop with massive amounts of silent, fast storage.

ASUSTOR Flashstor 12 - rear IO USB network HDMI

It's a little expensive for that purpose, but it could do it. There's nothing preventing you from running Windows on this machine. Or replacing ADM—ASUSTOR's own Busybox Linux-derivative OS—with something a bit more storage-focused, like TrueNAS!

So that's what I'm going to do today. ASUSTOR actually published a guide for installing TrueNAS, but I've added a few more details and I'll also show you how to back up ADM in case you accidentally mess up the factory install in the future!

Optional, but recommended - Back up ADM

The first thing I did, to make sure I would be able to restore my system to running ADM no matter what, is back up ADM from the Flashstor's built-in eMMC to another USB flash drive.

This is not required, especially if you disable the eMMC in BIOS (see the next section), but I like having the peace of mind, since (AFAICT) there's no way to download a copy ADM from ASUSTOR's website, at least not publicly.

  1. Plug in an empty USB flash drive
  2. Write a bootable Linux ISO to a different USB flash drive (I'm wrote Ubuntu 22.04 Desktop to a flash drive using Balena Etcher), and plug that in, too
  3. Boot the box with a monitor, keyboard, and mouse plugged in, and press F2 once the TianoCore splash screen appears
  4. In the BIOS, move to the left until you reach the Boot menu
  5. Scroll down to 'eMMC' entry, and press - repeatedly to move it to the bottom of the boot order (alternatively, go to the USB flash drive entry and press + repeatedly to move it to the top)
  6. Press F10 to save changes. Confirm, and reboot.

Once it reboots, it should boot into Ubuntu (or whatever Linux distro you had installed) instead of the built-in ADM OS.

Assuming you're booting from an Ubuntu ISO, when it asks, choose 'Try Ubuntu', and this will boot you into the desktop environment. Open a terminal, and run lsblk to verify you can see an mmcblk0 device (should be 8 GB), and your blank USB flash drive (something like sdb).

Make sure your blank USB flash drive (in my case sdb) is formatted and mounted. In my case, when I plugged in my exFAT or NTFS-formatted USB drive, Ubuntu identified it and automatically mounted it to /media/ubuntu/[volume label].

Ubuntu back up ADM

Now, the important part: use dd to clone the contents of the eMMC drive to the flash drive:

sudo dd if=/dev/mmcblk0 of=/path/to/usb/adm-image.img bs=16M

This will take a few minutes, but once it's complete, consider storing that ADM .img file somewhere safe so you can re-image the eMMC if you ever need to.

Optional, but recommended - Disable eMMC

Once you've made a backup of ADM from the eMMC, you could erase the eMMC drive and install Linux on top of it. But that's a bad idea, because (a) that eMMC drive is only 8 GB, which means you could run out of space on it pretty easily, and (b) it's easier to leave that volume in place and just boot from an external USB drive.

ASUSTOR BIOS - Disable eMMC support

So to disable the eMMC drive entirely, for safekeeping:

  1. Boot into BIOS (hold down F2 during boot)
  2. Go to Advanced > Intel Advanced Menu > PCH-IO Configuration > SCS Configuration
  3. Set eMMC 5.1 to 'Disabled'
  4. Press F10 to save changes. Confirm, and reboot.

If you reboot, it will likely just enter the UEFI Shell since it is set to boot only off eMMC from the factory. You have to go back into BIOS following the steps in the next section.

Install another OS

Assuming you've disabled the eMMC drive, you will now need to set up some other boot drive. I installed a cheap Kingston 120 GB SSD into a similarly cheap Inateck USB to SATA case, then plugged that into the blue (SuperSpeed) USB 3 plug on the back of the NAS.

I plugged my TrueNAS install USB flash drive into the front of the NAS, and then booted into BIOS by pressing the F2 key repeatedly once the TianoCore splash screen appeared.

I made sure the USB flash drive was set at the top of the boot order, pressed F10 to save changes, confirmed and rebooted, and was presented with the TrueNAS installer.

I followed the install wizard, making sure to choose the USB drive (and not one of the internal NVMe—though that is an option!).

ASUSTOR Flashstor 12 TrueNAS install success message

Once I rebooted (removing the install USB), TrueNAS completed its setup process and booted right up!

Accessing the web UI, I could complete the rest of the initialization process:

TrueNAS Storage display running on ASUSTOR Flashstor 12

Reverting to ADM

To go back to ADM, first re-enable the eMMC drive if you had previously disabled it, then go to the BIOS Boot Order menu and find the eMMC drive in the list, then press + to push it up to the top again. Press F10 to save the setting, reboot, and you'll be back to the ADM you know and love.

Is this supported?

It's permitted under ASUSTOR's warranty terms, but it looks like they don't provide technical support if you change OSes, since their NASes are sold as a kit with hardware + software combined. You can always switch back to ADM, though.

For full details, here's a still frame from their video about it:

ADM Notes for switching to another OS on an ASUSTOR NAS


How does TrueNAS perform on the Flashstor 12 Pro? Well, that's a topic I'll explore in an upcoming video. Subscribe to my YouTube channel so you don't miss it!


Possibly! Right now I'm just testing TrueNAS vs ADM. I might stick with ADM for now, just so I can manage it the same as my other spinning-disk NASes, but at some point I do want to get all my storage configs automated too.

Hello Jeff!

Great post. I am trying it on my FS6712X with the latest version of TrueNAS core (TrueNAS-13.0-U5.1.iso) however I am not getting a NIC detected after the install completes. Did you have any issues with this? Thanks!

I haven't had an issue, but I'm running Scale, not Core. I know traditionally Core (based on FreeBSD) has a few driver issues on newer hardware that isn't yet supported.

Hey Jeff,

I bought the Flashstor 12 and installed TrueNAS on it. There is an issue with TrueNAS CORE, it does not identify the 10gbic NIC. Yes it works in SCALE, but CORE is more stable for actual NAS type of functions (ie, more stable SMB).

I can't figure out how to get CORE to see the network card. Could you please, please, try and figure this out, see if you can get CORE to work with the Flashstor 12's 10Gbic NIC? It would help a great deal.


For some reason the current version of Core (based on FreeBSD) doesn't have the drivers for it. Scale does, since it's based on Linux and the kernel has the drivers for it built-in.

I would ask around on maybe ASUSTOR's support community site, or maybe on the r/asustor subreddit. I haven't personally tried getting the 10 GbE NIC driver working on Core.

I've found a general way of loading Aquantia drivers on CORE using this thread:

But I'm still having issues, no resolution as of yet. I'm definitely trying hard though!

Impossibile to find a way to do pcie passthrough of the nvme to truenas. Truenas need direct control of the storage for maximum performance

Hey Jeff,

I saw this article pop up in Google Chrome's news feed when I opened the browser on my phone. I was scrolling through and I saw your dd command.

I have a N5105 board (not Asus) that I have TrueNAS running on. I also have a Asustor 5304T so this is somewhat relevant. What I am wondering is if I was able to image the EMMC then write it to an SSD or NVME drive on my N5105 board, if it would actually boot. I'm wonder if it does any serial/hardware checks or if it would boot normally. Do we know if this is something that has been tried in the past? Reddit is a bit locked down at the moment... so I can't really check but this would open up some options here possibly to tinker before purchasing the Flashstor.

I'm not necessarily wanting to run ADM that is imaged from my AS5304T on the N5105 board, but if I could obtain an image from the Flashstor device, I'm thinking that *might* work.



Hey Jeff, have been following some of your recent pi videos and learning there's a whole lot more to you than that now! Hope the medical stuff is going well for you, Quick question about this device though, does it allow for Windows virtual machines like the QNAP devices do? Seems like a great machine though. Cheers.

Yes; in ADM you can run VirtualBox and run VMs inside of that, or you could install another OS on the box (though unsupported) and run whatever virtualization option you'd like there.

Hey Jeff.

Can you confirm if all 12 NVME bays are detected in true nas scale? I read somewhere online (can’t find the post now) that someone was having issues getting all drives detected in Linux.

Yes, they were. That user has been in contact with me; the issue seems to only affect certain drive types, and was due to a bug in the OS, which he had been able to patch.

Curious what drives, samsung 980pro 2tb's are on sale new for $100, was starting to consider one of these to replace my ancient synology finally, just want to make sure not those as the finicky disks. I use only samsung after like every other early ssd I tried would die with raid/encryption within 6 months, their auto-leveling seemed the only thing that worked, but seems their firmware has its own issues still...

Really curious how your experience has been with truenas with linux zfs on this. I never really trust these random chinese vendor operating systems any further than I can throw them, and about the only way I'd consider it. Likewise would like to see with encryption used, this is at a petite size I'd be worried about someone snatching it.

I do really wish even their 6 disk unit had a full mgig port that would do 1/2.5/5/10gbe. Network is always the last invited to the trough.

Well... The only one that is Chinese is Terramaster. Asustor, QNAP and Synology are Taiwanese and the operating systems on these devices are running standard busybox linux and primarily using the same open source components you'd find in any linux distribution. Perhaps check out some reviews before spreading misinformation based off of your prejudices? You literally cannot even avoid Taiwanese technology because it's inside the very device you are using right now to write this comment. Hardly random.

Did you have any trouble with CPU temp or fan control? I tried installing TrueNAS on an Asustor 6704 and found my CPU was in the 90c danger zone! Could not figure out how to control the fan.

I actually did notice the CPU hitting high temps under load (85-90°C), and couldn't figure out fan control. I have asked ASUSTOR about this and hopefully will have more to report back!

Did you ever get a response from asustor? I want to put truenas on my asustor, but I'm worried my fan won't work, as it's been behaving abnormally with ADM. Maybe you got it working?

Bought 2 flashtor 12 pro upgraded to 16GB ram (40$)or is almost useless with ZFS.
In one we have installed TrueNas Core on one internal nvme(500GB, 30$) and the boat loader on the eMMC.
10GBe NiC working good, you must install the freeBSD driver. Config: 1(4 TB, 190$) nvme set for LARC2, 1 nvme for ZIL(4TB, 190$) the other 9(cheap 2TB) in raid-z2 (double parity)
for a total capacity of ZFS usable(20 % free space limit)
12TiB cost for the 9 nvme (765$)
Total cost: 800+40+30+190+190+765= 2015$
Don't know if the LARC2 and ZIL Nvme are a good idea but they are working properly and they must lower the usage of the other Nvme while editing (and recording).
This is the solution we use in the small editing van on the road.

We also have a one with a slightly different configuration: TrueNAS scale 16GB ram, 1nvme boot 500Gb, 11 Nvme(2TB, 85$) with raid-z3(triple parity), the cost is 210$ less(total 1805$) for 14 TiB ZFS usable(20 % free space limit).
We use this on set for backup during the shooting and we plug the external SSD directly to the NAS with USB and we copy using a custom UI running on a custom in house docker and optionally uploading to or to a a S3 storage directly from the same UI, The footage are also available on the minIO sever (running on another Docker in the NAS). One of the USB port can be configured to use a 5G USB key connection or a smartphone for the remote backup.
This is a bargain solution with very high security (accepted by our shooting insurance). About power consumption: we never spike over 35watt including the 5G USB key and we run this on a big power bank for the whole day.
Hope that helps.
Jeff Hightower (tech advisors at Msvs)

Do you have any guide, how to install the driver for freeBSD and which driver do you use?
You would help me tremendous to get TrueNAS Core working on the Flashstor.

Hello, I have recently moved to another country and wanted to rebuild my home lab. I have bought the FS6706T and was also looking to install TrueNAS Scale on the machine after seeing this blog post as I am more familiar with the operating system. However, I don't seem to get any video signal on boot even after trying with two of the monitors I have on hand through the HDMI port, so I cannot access the BIOS page. One of the monitor is the LG 27GN950-B and the other is the Asus VA246HE. Are there any fix around this?

Update: I downgraded my RAM to the default stick of Apacer 4GB DDR4, and now I could see the TianoCore boot logo. However, even though I immediately started spamming F2 on my keyboard (which is getting power since the backlight lit up), I could not go into the BIOS and the system booted into ADM every time. I made sure that my keyboard wasn't hiding F2 in the second layer but it did not work. I am stuck at a different problem right now.

My flashstor 12 runs just fine with 32GB of Crucial RAM I ordered off Amazon - Crucial RAM DDR4 3200MHz CL22 32GB Kit CT2K16G4SFRA32A and allows access to the boot bios using that memory.

Another post on Reddit mentioned a similar situation with the keyboard not being recognized. They switched to a different USB port which resolved their issue, try swapping around the port you're using and see if that helps.

Any worries running ZFS with non-ECC RAM? Currently I run a Truenas core box on a DL380 1 pool, 2x 6disk Z2 Vdevs. Need to migrate to something much less power hungry as 300-400w is a bit much. My concern with going to the Asustor is not having the ECC memory on ZFS

Hi Jeff.
Is N5105 powerful enough to run Truenas?

I have a plan to install Truenas on NAS which is called EFM NAS400 (designed by Korean company EFM and it has N5105)
and just want to know Truenas would not have any performance issue due to performance of N5105.

Also, just in case you may be interested to know EFM NAS400.
I believe that EFM NAS400 is the cheapest 4-bay NAS with N5105 in the market.
It is 345 dollars and has following ports with clean looking chassis
- 3.5 inch bay x 4
- RJ-45 2.5Gb LAN x 2,
- USB 3.2 Gen 1x1 x 2,
- miniHDMI x1
- 4GB EMMC x1,
- DDR4 SO-DIMM x1, (Default 4GB, but upgradable to 32GB)

Sadly, this machine is only available in Korea for now.

N5105 can run TrueNAS just fine, though it's probably best for builds that use 2.5 Gbps (which it seems like you're attempting). It doesn't have the power to really saturate 10 Gbps.

Hello Jeff,

After reading your review, I was convinced, and ended up purchasing a Flashstor myself. However I am having trouble at the part where you press "F2" after the TianoCore screen. After the TianoCore screen, regardless of whether I press "F2" or not, I get a black screen with a flashing cursor. In fact at this point I have never seen a GUI at all, aside from the TianoCore logo. Have you encountered this? Does this seem like a faulty unit to you?

I have not seen that behavior. On your keyboard, do you have to hold down a 'Fn' key as well to get F2 to register?

The blinking cursor just means the ASUSTOR booted into whatever it's normal ADM OS is.

Hi Jeff,

Knowing the flashing cursor wasn't some failure to load an OS was reassuring at least. For posterity's sake, suspecting the Flashstor to be very picky with keyboards as described by others online, I went and purchased the cheapest USB wired keyboard I could find. The spacebar won't even register unless pressed exactly in the middle. It should be criminal to manufacture something as crappy as this.

I've now backed up ADM as per your instructions and Proxmox is up and running (TrueNAS, although very powerful, was not right for me). The experimentation begins...

Heh... it reminds me of when I would test out computers using the cheap wired keyboards shipped with some of the low end Dells back in the day. Pressing a key would deflect the entire keyboard a bit!