Hello Kay,
On Mon, 5 Feb 2018 16:27:19 +0100 Kay Diederichs kay.diederichs@uni-konstanz.de wrote:
On 02/01/2018 12:15 PM, wwp wrote:
Hello there,
Dell XPS-15-9560 laptop (SSD drive, UEFI, secure boot off).. Windows 10 pre-installed, CentOS7 installed in a separate partition and running for months w/o issue. Don't know what happened but at reboot yesterday (not even booted in Windows, just rebooted), grub has disappeared, booted in Windows by default, which apparently has taken over the UEFI boot.
The DELL XPS-13-9360 in its BIOS has an option (named "auto boot recovery" or similar - sorry the machine is somewhere else) that is by default enabled. I guess you have it enabled as well.
This option is triggered by two unsuccessful boot trials, and leads to the loss of the grub menu, and restoration of the (non-grub) "Windows boot manager" (or whatever it's called).
After being bit by it once, I disabled it.
At last I could reboot the system, and could verify that, you're right, there's a Bios option to restore factory settings in case of a (more or less) parametrable amount of boot failures. I disabled it as well, this is way too dangerous in case of booting from USB flashdrives (for instance) and can be enabled back if it's really needed. Thanks!
Regards,