Windows missing in Grub2 Efi menu

[malcolmlewis]

What makes you believe /boot/efi is /dev/sdb2 and not /dev/sda2?

Hi
Could be, but this is actually labelled as the efi partition....

/dev/sdb2: UUID="2004-0144" TYPE="vfat" PARTLABEL="EFI system partition" PARTUUID="509772ac-8c8c-40d2-98be-38f1f541160d"

[Tarp]

I tried booting from a Win10 media and found out that it was not able to boot or even install with the given partition.I then tried to reinstall windows on a wiped sdb drive - still without success. It kept claiming that the efi-system disk was of wrong format, even though I had carefully formatted it as the required FAT32.

So I thought that it could be that the presence of sda disk (with its partitions) was confusing the windows installer, so as a final resort I physically unplugged the sda disk.
I was then able to install Windows from scratch at the sdb disk.

After re-plugging the sda disk, grub perfectly finds the Win 10 system and I am calm and can continue scanning old slides - which is the only reason I have to keep Win 10.
Thanks for the help!

[brunomcl]

FWIW

I have two boxes running 15.1 and 15.2 Plasma, both dual-booting with windows 10.
Every now and then grub loses the windows entry, AFAICS after an update.
The simplest way to fix this, for me, is to go into Yast>bootloader, check that "probe foreign OS" is checked (it always is), make a minor edit (like the boot menu timeout), and save changes. Then windows entry is back.

[arvidjaar]

Every now and then grub loses the windows entry, AFAICS after an update.

After update of Windows or Linux? Do you use legacy BIOS or UEFI boot?

[brunomcl]

After update of Windows or Linux? Do you use legacy BIOS or UEFI boot?

Linux & UEFI. Larger Windows updates sometimes make the boxes boot straight into it, losing the grub menu entirely. Fixing this is also simple: boot into openSUSE from UEFI and run Yast's bootloader again.

[arvidjaar]

Linux & UEFI. Larger Windows updates sometimes make the boxes boot straight into it, losing the grub menu entirely.

This is completely opposite to what you stated before.

Every now and then grub loses the windows entry,

[brunomcl]

This is completely opposite to what you stated before.

Before I was commenting on the OP issue. Then you asked "After update of Windows or Linux?", so I commented that it also happened sometimes after windows update, but that it kills grub entirely, booting straight to windows.

Sorry if it confused you.