On 6/27/19 10:27 AM, Robert Heller wrote: > Actually*grub* needs access to /boot to load the kernel. I don't believe that > grub can access (software) RAID filesystems. RAID1 is effectively an exception > because it is just a mirror set and grub can [RO] access any one of the mirror > set elements as a standalone disk. Note that UEFI partitions can't be RAID at > all (and are FAT filesystems) and need to be accessable by the BIOS / boot > EEPROM. /boot/efi has the same exception, as long as you use metadata format 1.0. Early versions of CentOS 7 did not allow the use of RAID 1, because it was possible in theory for the firmware or for an alternate OS that shared the EFI partition to modify the filesystem and invalidate the mirror. That restriction has been removed, and Anaconda will now allow you to create /boot/efi as a RAID1 device. This should be mostly safe as long as your Linux OS is the only OS that modifies the EFI filesystem.