This is a bizarre one.
I boot into Linux from a USB flash drive. This USB stick was plugged into the top front USB port and booted (legacy mode) fine from that. Then one day the BIOS would report there was no bootable media available.
So I moved the USB stick to the back far right port (viewing from behind). It booted fine. Then one day the BIOS would report there was no bootable media available. So I tried moving it to the port I'd been using before (front top) but still wouldn't boot.
So I moved the USB stick to the back far left port (viewing from behind). It booted fine.
I'm scared the BIOS is gradually freezing out USB ports I can boot from. I'm worried that soon I'll run out of USB ports I can boot from.
Anybody else had this problem? What could it possibly be?
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What could it possibly be?
I suggest that you try another USB drive. This could be an issue with the USB drive or other hardware in the system. Hardware that is not validated can cause odd issues throughout the system. You should remove or swap hardware to try to locate the problem device.
If the USB ports are still functional then it is likely the act of reseating or retrying the USB drive that is allowing it to eventually boot successfully. If the USB ports are no longer functional after using this USB drive in them then the USB drive may be physically damaging the ports.
Dell EMC, Enterprise Engineer
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Thank you for your response. Unfortunately that answer does not correlate with the symptoms: the USB works fine, is written to, is read from, the operating system once booted.
But any USB port previously used for a boot is no longer recognises bootable media in that USB port. This seems to be a serious BIOS issue.
When will a BIOS fix be available that allows a USB port to be used more than once for booting in legacy mode?
I'm with I have a issue like that with my dell t20 I'm using unraid on a USB and when I plug in a formatted second USB drive for storage the dell t20 wont boot its like it reads the blank usb rather than the USB thumb drive with unraid on it even thou I have it set in the bios to boot from the sandisk usb with unraid on it if I get some time this weekend I can make a youtube video showing the issue also I am on the latest bios update from dell. any ideas?
I believe I've found a solution.
When I boot I press F12 to activate the one-time boot menu. It gives me options and I select the "USB Storage Device" option under "LEGACY BOOT". The first time it works, but the next time I try I get:
Selected boot device failed. Press any key to reboot the system.
It simply involves booting, pressing F12 to activate the one-time boot menu, and then selecting the option "BIOS Setup" under "OTHER OPTIONS". Then exit the setup, the server will reboot, and it will boot off that USB the next time!