TerraMaster Forum

Some new NAS devices use a customized USB drive to store the initboot initialization program. To help users understand how to handle this USB drive (including removal and disabling), the following provides detailed information, including the applicable models, USB drive appearance, and steps for adjusting the BIOS boot order.

Applicable Models
F2-425, F2-425 Plus, F4-425, F4-425 Plus, F4 SSD



Note
As shown in the illustration, the new NAS devices use a customized internal USB drive.

Important Notes

1.The internal USB drive is used as the initboot system boot disk. Do not remove or replace it arbitrarily, as this may prevent the device from booting properly.

2.If you need to install a third-party operating system or adjust the boot sequence, you must enter the BIOS and modify the boot options by following the steps below.

Steps to Adjust BIOS Boot Order

1.After entering the BIOS interface, use the keyboard arrow keys to navigate to the Boot tab.

2.Select TOS Boot First and press Enter. Change its status from Enabled to Disabled, then press Enter again to confirm and return.



3.Select Boot Option #1 and press Enter. Use the up/down arrow keys to choose the desired boot device, then press Enter to confirm and exit.




4.After confirming all settings are correct, press F4 to save and exit.

I must confess to being slightly confused when I came to set up my F2-425+ this week. Never
expecting to own such a device, I had not paid attention to the internals. I had to do a double
take when I did not see a usb drive in the expected slot! Was there another usb 'A' slot?? A little
research solved that conundrum!

Rather than "customised usb drive", maybe a term such as "USB-DOM" to clearly distinguish between
this and a standard flash drive.

Thanks for the post.

Could you clarify if the F2-425+ uses a USB-DOM instead of a standard USB drive?

izedgrudged wrote: ↑25 Mar 2026, 14:49 Could you clarify if the F2-425+ uses a USB-DOM instead of a standard USB drive?geo dash

Your judgment is correct. Currently, F2-425+ is using USB-DOM.

Very odd and so far only on this post, this is flagged. The images do not display on the original post, but this pops up for me.

rfbjr wrote: ↑26 Mar 2026, 21:56

I don't use MS Edge, but I tried it - no issues with warnings.

I'll try it with Firefox and Chrome, could be something I need to tweak within Malwarebytes.

I'm stuck on this prompt after installing 2 x m.2 drives and moving system disk to those. It seems to boot up but I can't get further in the web interface. Mobile access seems to work so I don't know what I'm doing wrong.

Sander wrote: ↑02 Jul 2026, 00:18

May I ask what your device model is?

EriChan wrote: ↑02 Jul 2026, 17:24

Sander wrote: ↑02 Jul 2026, 00:18

May I ask what your device model is?

I have a F4-425 Plus with TOS 7.0.0765.

Everything works with accessing files, using mobile app etc but I can not use the web interface. It only has a button for Shut Down with no other options. Sounds like a software bug because it makes no sense. I did everything in the message but no change. I have restarted it multiple times.