On May 28, 2018, at 18:25, Robert Heller <heller at deepsoft.com> wrote: > I tried to run efibootmgr, but it wants a model named efivars loaded, but > there is no such module available. Are you not running a CentOS kernel? That module should be available. The UUID of the VFAT volume (not the mirror) would be used in the EFI boot entry. Boot off a rescue disk when the new disk is installed and add an additional boot entry for the new disk. It will reflect the UUID of the EFI partition on the new disk. Run ‘blkid’ to compare. -- Jonathan Billings