On Thu, Aug 18, 2016 at 11:57 AM, James A. Peltier <jpeltier at sfu.ca> wrote: > Hi All, > > I have a Dell R710 that has 6x1TB in a RAID-5 configuration. This is hardware RAID 5? Because it's pretty screwy how this ends up working when using software RAID and might take additional troubleshooting. > When installing CentOS 7 using the full disk capacity and booting in UEFI mode the machine dumps me into a GRUB rescue mode prompt. > error: disk `,gpt2' not found > Entering rescue mode... > grub rescue> This is confusing to me because there should be no such thing as grub rescue on UEFI. On BIOS systems, there is boot.img (formerly stage 1) and core.img in the MBR gap or on BIOS Boot if GPT disk (formerly stage 1.5 and stage 2). The core.img is where grub rescue comes from when it can't find grub modules, in particular normal.mod. But on UEFI, core.img, normal.mod, and a pile of other modules are all baked into the grubx64.efi file founds on the EFI system partition. I suspect two things that can cause normal.mod to not be found: a. The system is not in fact booting in UEFI mode and there's been some mistake in the installation of grub. b. The system is in UEFI mode, but either the installer, or post-install, grub2-install was run which obliterates the grub2-efi package installed grubx64.efi, i.e. it's not really proper to run grub2-install on UEFI systems. Boot off install media with boot parameter inst.rescue and choose all the default options; this ought to assemble the file system per fstab, and you can chroot /mnt/sysimage yum reinstall grub2-efi efibootmgr -v grep efibootmgr /var/log/anaconda/program.log ## I think that's right it might be anaconda.program.log though It's really just reinstalling grub2-efi that should fix the problem, the following two options are just information gathering in case the reboot still doesn't work. -- Chris Murphy