I just set up a fresh install of CentOS 7.2, and after doing yum update, I can not boot into my machine. The kernel was updated, I can see both kernels in GRUB2, but I cannot boot into either of them, I cannot even boot into the rescue kernel. When I do the monitor goes black and does not come back, or stalls during boot and won't respond to any key presses. I think I forgot to do a grub2-mkconfig -o /boot/grub2/grub.cfg possibly? Any advice?

Edit: single user works for original kernel. But if I try single user with new kernel the monitor goes black. I must have gotten a bad nouveau driver or something

2 Answers 2

  • get a rescue image on a usb stick or cd
  • try nomodeset kernel arg (or try removing it)
  • can you boot into single user mode? (stick 'single' on the end of the kernel args)
  • I can get into single user for the old kernel. Not the new kernel Jan 20, 2017 at 22:33
  • And, when I switch to graphical mode that is when it stops working. I will see if I can yum history undo $everything Jan 20, 2017 at 22:46
  • Nomodeset seems to work. I guess there is an issue with xorg or gdm? May 4, 2017 at 18:59
  • Actually, the opposite is true. Nomodeset tells the kernel not to try and use the video driver directly. With nomodeset, the kernel uses a generic video driver. The only time that should really be a problem is when you want a super snazy 4K splash screen during bootup, or something. Otherwise once you get X working, you shouldn't notice.
    – pileofrogs
    May 4, 2017 at 19:10

If grub boot is causing you problems, then open rescue kernel

yum remove kernel.....(new one)
yum update (now your new kernel should work fine)
  • 1
    "I cannot even boot into the rescue kernel" - From the question.
    – Centimane
    May 4, 2017 at 18:47

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