Greg Wooledge composed on 2021-06-11 15:07 (UTC-0400): > On Fri, Jun 11, 2021 at 09:38:37PM +0300, Semih Ozlem wrote:
>> How to check where grub is installed? And what is a friendly guide to >> learning about grub? > GRUB should be installed on the *disk* (not on a partition) that you > intend to boot. > Not to detract from the wisdom of the rest of Greg's excellent reply, but TBC, this statement is religion at one extreme, opinion at the other, not fact. Note he wisely did not say "must", but "should". For most traditional (BIOS/MBR; designed for "Windows" PCs) configurations, it's probably prudent to put the bootloader on the "disk". For pure Debian installations, as opposed to multiboot, whether or not to install it on the "disk" really doesn't matter. OTOH, putting a bootloader on the MBR of a disk on a PC designed for Windows is a relative newcomer to the world of booting such a PC. I've been installing operating systems on IBM-compatible PCs for more than 3 decades. Not once have I intentionally installed Grub on an MBR. In the dearth of instances where it did happen I wiped whatever caused it, and started over with DOS/OS2/Windows/Linux-compatible MBR code on the MBR. IOW, Grub can live elsewhere than on the MBR. A less innocuous error is not clearly qualifying the quoted statement to apply only to non-UEFI boot environments, which usually means an MBR-partitioned boot disk. On a UEFI installation, which requires GPT partitioning, the first sector normally contains nothing until near its end, where a disk identifier and the start of the disk's multi-sector partition table begin. No executable code is required on this sector. With a UEFI "BIOS", the boot process begins rather differently than on an MBR-only system. On a UEFI system's ESP (Extensible Firmware Interface System Partition; a quasi-"boot" partition), there are no files containing the string "grub" in their name. Thus it seems to be a debatable issue whether "bootloader" is actually an appropriate name for Grub 2, as its primary purpose seems to be presenting a menu from which to select what kernel, initrd (if any), and kernel command line parameters (if any) to load into RAM to /continue/ the boot process initiated by the UEFI firmware. -- Evolution as taught in public schools is, like religion, based on faith, not based on science. Team OS/2 ** Reg. Linux User #211409 ** a11y rocks! Felix Miata