Everything was running fine

I updated from 7.3.2 to 7.3.3
When it said to reboot after update, i did.

Nothing.

After attaching a monitor to the server, the Computer IS set to boot from USB in the bios and the usb device is found on boot. Have tied to reboot an all USB ports.. USB is recommended Samsung drive less than a year old.

I cant find in docs the way to trouble shopot this situaltion.

Will there be anything I can recover from the USB?

PLEASE PLEASE Can someone point me to where its documented how to troubleshoot this.

Pull the USB drive and plug it into a Windows PC first.

Look for a folder named config and copy the entire thing to your desktop immediately.

That folder contains your license key, array configuration, network settings, and Docker templates. As long as you have it your configuration can be fully restored.

If the drive is readable on Windows the issue is likely the bootloader rather than drive failure.

Download the Unraid zip for 7.3.3, extract it to the USB drive formatted FAT32 labeled UNRAID, then right click make_bootable.bat and run as Administrator.

Copy your saved config folder back onto the drive.

Also check whether there’s an EFI- folder with a trailing hyphen -- rename it to EFI if so.

If the drive isn’t readable at all it’s failed and you’ll need a fresh drive.

Either way -- when replacing the Samsung, that recommendation is outdated and the drive has a documented history of problems in Unraid.

Get a reliable drive as a replacement:

https://forums.unraid.net/topic/199642-psa-on-industrial-mlc-usb-boot-drives-mlc-nand-end-of-life-and-last-accessible-stock

If the flash drive is still readdable, try recreating it as a first step, first backup the current one, then recreate it using the USB tool with 7.3.3, confirm the flash drive boots with the stock install, and if yes, restore only the /config folder from the backup overwriting any existing files.

@JorgeB @Lolight Thanks for the answers. Very much apreciated

So just to be clear.The ONLY folder that has all my settings docker, anything that is "mine" is in the config folder?
And Im assuming instructions the same on linux?

Correct

@JorgeB thanks.

Tried with installer on linux (7.3.2 latest with installer) No Boot

Tried a new brand USB Exactly the same samsung metal type and no boot also. I live far from stores and deliveries
Bios set to boot from USB. USB is first in bios drive order
Boot dialog sees the USB storage device but still cannot boot,
goes to a black screen with blinking curser top left just as after the update originally

Are you booting legacy or UEFI? Legacy boot requires running make_bootbale first. You can also test if the flash drive boots on another PC, if available.

UEFI. its the same results now as pre reinstall on both drives. I will test on another computer when I can. the next server wil def be NOT booting from USB.

Go into BIOS and check two things:

First, find Secure Boot and disable it if enabled.

Second, find CSM (Compatibility Support Module) and try toggling it -- if it’s enabled try disabling it or vice versa.

It really sounds like a UEFI/Secure Boot/CSM conflict rather than anything wrong with the drive or Unraid installation.

Also check whether the EFI folder on the drive has a trailing hyphen -- EFI- instead of EFI. If so remove the hyphen.

Cannot find anyCSM Or Secure Boot Probably too old.
EFI folser has no trailing -

I thought my bios was UEFI but it's probably legacy
Im using the Unraid creator. Whats make_bootable and how can i run it? (linux)

https://docs.unraid.net/unraid-os/getting-started/set-up-unraid/create-your-bootable-media/#finish-the-usb-setup