I have a laptop with two installed M.2 SSDs. One had Windows installed. I then installed Linux Mint (LM) on the second one through USB, and was able to set up a Grub boot menu that showed both Linux Mint and Windows.
Recently, I tried to add CentOS to this list by creating a partition on the second drive that contained LM. I then updated grub to add CentOS to the list but I think it got rid of Windows. So I couldn’t boot into Windows. I was unable to see Windows in LM. I couldn’t see the drive with GParted and os-prober said
/dev/sdb: open failed: No medium found
Somehow, I was able to get Windows to appear in grub again, and I could see the disk that had Windows in GParted. However, booting into Windows didn’t work and I would get sent to the blue screen recovery menu (when in the command prompt, it said the C: drive was RAW). At some point, I don’t remember how, maybe by switching to Legacy OS and back to UEFI in my UEFI settings, I could finally boot into Windows and not get sent to the recovery menu (from grub). However, when I go back to LM, I get the same issues as before where I can’t see the Windows drive and os-prober can’t open /dev/sdb.
Now, I’m afraid that if I run grub-update it will get rid of Windows again. Is there any way to get Windows to show up on os-prober and not get removed by grub-update? I think I disabled hibernate through powercfg if that matters. Let me know if you need more info.
FWIW, I want to resolve this issue in case I need to reinstall some OSs in the future. I am ok with wiping the drive containing the Linux distros. And I may have to, as it seems I can’t get into CentOS anymore. I would prefer not to reinstall Windows or wipe that drive since I have a bunch of data. I am getting this dracut output from booting CentOS, which may be related.
