@@ Line 1: / Line 1: @@
+Notes;
+*LVM on NVMe is the issue
 Rocky Linux 9 does not use the /etc/default/grub and /boot/grub2/grub.cfg Files any longer.  Instead the BLS (Boot Loader Specification) 'method' is used.  If one reads the documentation from RedHat, it seems like thing got really messy (and confusing).
+====Quick D for Cloning, err, "Recreating" a drive from a BackUp (IE, the closest thing to Acronis that Linux seems to have)====
+*Create a duplicate or functionally similar Partition layout to the original
+**CFDISK and "Logical Volume Commands"
+**Use Blivet from a Rocky 8 Live Boot Device<br />
+====Rough D====
+*Start from a 'Clean Slate': <code>wipefs -a /dev/sdX</code> (make dang sure the proper 'sdX' is chosen!)
+*Set the Partition Type (MBR or GPT): <code>cfdisk /dev/sdX</code>, (select DOS or GPT, save it (write) )
+*Create Partitions: cfdisk
+**https://en.wikipedia.org/wiki/Partition_type
+**Linux EXT4: $83 (that's Commodore Speaky for 83h)
+**Linux LVM (and LVM2): $8E
+*LVM Stuff using Commands or BLIVET (sadly only Rocky Linux 8)
+**<code>pvcreate /dev/sdXy</code>
+**<code>vgcreate VG.NVMe.ROOT /dev/sdXy</code>
+***<code>vgrename WhatEverOldName WhatEverNewName</code>
+**<code>lvcreate -L 64G -n LV.ROOT VG.NVMe.ROOT</code>
+*Format Partitions
+**mkfs.vfat -F32 /dev/sdXy
+**<code>mkfs.ext4 -v -L ROOT.EXT4 /dev/sdXy ( -v = Verbose, -L = Label )</code>
+**<code>mkswap -L SWAP /dev/sdaXy</code>
+*MBR Stuff if desired
+*UEFI Stuff ("make" the grubx64.efi File) --- Best done from a UEFI system!
+**grub2-mkstandalone is a similar command
+**Make sure UEFI Stuff is installed (if cloning from an MBR / BIOS based system);
+***dnf install grub2-efi-x64 grub2-tools grub2-tools-efi grub2-tools-extra grub2-efi-x64-modules efibootmgr shim-x64
+**<code>mkdir /mnt/efi</code>
+**<code>mount /dev/nvme0n1p1 /mnt/efi</code>
+**<code>grub2-install --target=x86_64-efi --efi-directory=/mnt/efi --bootloader-id=rocky --recheck --force --verbose --modules="part_gpt ext2 fat normal search search_fs_uuid search_fs_file configfile all_video gfxterm gzio" **--no-nvram** **--removable**</code>
+***--force = Do it on a supposedly 'non-secure' system
+***--no-nvram = Do it even if a target drive is being prepared as a UEFI Booted system even if the current OS is an MBR / BIOS system
+***--removable is optional and installs the 'generic' BOOTX64.EFI File. )
+***--modules because apparently absolutely no modules are installed by default, even ext2!
+****...and if you've got loads of space, then load up grubx64.efi with everything: --modules="$(ls /boot/grub2/x86_64-efi/ | sed 's/\.mod//g' | tr '\n' ' ')"
+**Command to show information on how a system was booted (and can boot): <code>bootctl status</code>
+**Command for EFIBootMgr: <code>efibootmgr -v</code>
+*GRUB Menu stuff
+**Edit: /etc/default/grub
+**Make the grub.cfg file: grub2-mkconfig -o /boot/grub2/grub.cfg
+**Seemingly useless command (as a text editor would work, no matter the 'threats' in the file): grub2-editenv
+***Wait, spoke too soon.  If this error is encountered: grub2-editenv: error: environment block too small. when using kernel-install it indicates the grubenv file isn't 1024 bytes.  Seems like the grub2-editenv tool pads the file with ###### symbols to make it exactly 1024 Bytes (and we know how important it is to have a file equal to exactly 1024 Bytes!)
+**grub2-probe: General information, simple
+*Kernel Stuff (initramfs, vmlinuz, bootloader entries, etc.): kernel-install
+**to 'redo' VMLinuz Stuff: dracut
+*Edit / Register the entry in the Hardwares UEFI Storage space
+**efibootmgr --create --disk /dev/nvme0n1 --part 1 --loader '\EFI\rocky\grubx64.efi' --label "Custom GRUB" --bootorder 0001
+*Edit the BLS (Boot Loader System) Entries, etc.
+**GRUBBY
+*Restore BOOT and ROOT File Systems
+**f
+**f
+*Modify Entries in;
+**/boot/loader/entries (wherever mounted)
+**/etc/fstab (wherever mounted)
+*...and the tribulations continue as the below command won't work from an MBR / BIOS system or theoretically from any system that isn't the one being booted, run from etc.;
+**Entry for Hardware Firmware (AKA BIOS Settings): efibootmgr --create --disk /dev/sdb --part 1 --loader /EFI/rocky/grubx64.efi --label "Rocky Linux" --verbose
+**Work Around:
 ====BLS (Boot Loader Specification)====
@@ Line 9: / Line 73: @@
 Look in /boot/loader/entries and / or use GRUBBY
+...see below for key information on /etc/default/grub and BLS
 ====GRUB "Installation" for MBR / BIOS====
@@ Line 66: / Line 132: @@
 *On '''UEFI systems''', <code>grub2-install</code> registers <code>grubx64.efi</code> with the UEFI boot manager using <code>efibootmgr</code>.
+===More from ChatGPT on "GRUBing"===
+='''Comprehensive Guide to Installing GRUB on Rocky Linux (UEFI & BIOS)'''=
+This guide covers:
+*'''UEFI bootloader installation''' on a target drive.
+*'''Legacy BIOS (MBR) bootloader installation'''.
+*'''BLS (Boot Loader Specification) and its effect on <code>grub2-mkconfig</code>.'''
+*'''GRUB Boot Stages Explanation (Stage 1, Stage 1.5, Stage 2).'''
+*'''How to properly configure bootloader entries and verify installation.'''
+----
+=='''1. Understanding GRUB Boot Stages'''==
+{| class="wikitable"
+!'''GRUB Stage'''
+!'''Description'''
+!'''Applies To'''
+|-
+|'''Stage 1'''
+|'''MBR code''' (first 512 bytes of disk) loads Stage 1.5 or Stage 2.
+|'''Legacy BIOS (MBR) Only'''
+|-
+|'''Stage 1.5'''
+|Located in the first 30KB after MBR, it helps find <code>/boot/grub2</code>.
+|'''Legacy BIOS (MBR) Only'''
+|-
+|'''Stage 2'''
+|Loads the GRUB menu, kernel, and initrd.
+|'''Both UEFI and BIOS'''
+|-
+|'''UEFI Firmware Boot'''
+|Uses the '''EFI System Partition (ESP)''' instead of MBR. Loads <code>grubx64.efi</code>.
+|'''UEFI Only'''
+|}
+----
+=='''2. Installing GRUB for UEFI Booting'''==
+==='''A. Identify the Target Drive'''===
+List available drives and partitions:
+Look for the '''EFI System Partition (ESP)''', usually '''formatted as FAT32 (<code>vfat</code>)'''.
+Example: If the target drive is <code>/dev/sdb</code>, and the EFI partition is <code>/dev/sdb1</code>, mount it:
+==='''B. Bind System Directories (for Chroot)'''===
+If configuring an external system:
+==='''C. Install Required UEFI GRUB Packages'''===
+==='''D. Install GRUB to the Target Drive'''===
+*<code>--target=x86_64-efi</code> → Specifies '''UEFI mode'''.
+*<code>--efi-directory=/boot/efi</code> → Ensures GRUB is installed in the EFI partition.
+*<code>--bootloader-id=rocky</code> → Labels the boot entry as '''"Rocky"'''.
+*<code>--recheck</code> → Forces a re-scan of the drive layout.
+==='''E. Generate the GRUB Configuration'''===
+⚠ '''However, Rocky Linux follows BLS, which makes this step less critical''' (explained in Section 4).
+----
+=='''3. Installing GRUB for Legacy BIOS (MBR Boot)'''==
+==='''A. Mount the Target Drive's Root Partition'''===
+If the system has a separate <code>/boot</code> partition:
+==='''B. Chroot into the Target System'''===
+==='''C. Install Required BIOS GRUB Packages'''===
+==='''D. Install GRUB to the MBR of the Target Drive'''===
+*<code>--target=i386-pc</code> → '''Required for Legacy BIOS (MBR) booting'''.
+*<code>/dev/sdb</code> → '''Must be the whole disk (not a partition like <code>/dev/sdb1</code>)'''.
+*<code>--recheck</code> → Forces a disk layout rescan.
+==='''E. Generate the GRUB Configuration'''===
+⚠ '''But due to BLS, <code>grub.cfg</code> is no longer the main configuration source.'''
+----
+=='''4. Understanding BLS (Boot Loader Specification)'''==
+Rocky Linux follows '''BLS (Boot Loader Specification)''', meaning '''boot entries are controlled by systemd-boot entries, not <code>grub2-mkconfig</code>'''.
+==='''How to Manually Manage BLS Entries'''===
+#'''List Existing Boot Entries:'''
+#'''Manually Create a BLS Entry:'''
+#'''Example BLS Entry (<code>rocky.conf</code>)'''
+#'''Enable BLS Support in GRUB (if needed)'''
+==='''Why BLS Makes <code>grub2-mkconfig</code> Less Relevant'''===
+*'''Traditional GRUB entries are no longer used''' in Rocky Linux.
+*The '''bootloader reads BLS entries instead'''.
+*'''<code>grub.cfg</code> is still used for bootloader settings''', but '''kernel entries are controlled by BLS'''.
+----
+=='''5. Verify Installation'''==
+==='''Check EFI Boot Entries (For UEFI Only)'''===
+==='''Check GRUB Installation'''===
+==='''Check BLS Entries'''===
+==='''Reboot and Test'''===
+----
+=='''6. Summary'''==
+{| class="wikitable"
+!'''Boot Mode'''
+!'''Target Option for GRUB'''
+!'''Install Command'''
+!'''Config Location'''
+|-
+|'''UEFI'''
+|<code>x86_64-efi</code>
+|<code>grub2-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=rocky</code>
+|<code>/boot/efi/EFI/rocky/grub.cfg</code>
+|-
+|'''BIOS (MBR)'''
+|<code>i386-pc</code>
+|<code>grub2-install --target=i386-pc /dev/sdb</code>
+|<code>/boot/grub2/grub.cfg</code>
+|-
+|'''BLS (Rocky Linux Default)'''
+|<code>systemd-boot controlled</code>
+|<code>bootctl list</code>
+|<code>/boot/loader/entries/</code>
+|}
 <br />
+=='''1. The Presence (or Absence) of <code>/boot/grub2/grub.cfg</code>'''==
+*If '''<code>grub.cfg</code> exists''', GRUB will parse it.
+*If '''<code>grub.cfg</code> does NOT exist''', GRUB will attempt to '''read the BLS entries directly''' instead.
+This means:
+✔ '''Deleting <code>grub.cfg</code> forces GRUB to rely entirely on BLS.'''
+✔ '''Regenerating <code>grub.cfg</code> (<code>grub2-mkconfig</code>) puts GRUB back into a "hybrid mode" where it may still reference BLS but also maintain compatibility with legacy boot setups.'''
+----
+=='''2. GRUB’s Bootloader Installation (<code>grub2-install</code>)'''==
+The actual bootloader installed to the disk controls whether it defaults to '''BLS mode or <code>grub.cfg</code> mode'''.
+When GRUB is installed with:
+(''where <code>/dev/sdX</code> is your boot disk, like <code>/dev/sda</code> or <code>/dev/nvme0n1</code>''), it does the following:
+*Sets up '''GRUB’s core image''' (<code>/boot/grub2/i386-pc/core.img</code> for BIOS systems or <code>/boot/efi/EFI/rocky/grubx64.efi</code> for UEFI systems).
+*Embeds the logic for '''how GRUB will find and load boot entries'''.
+*If BLS is active, it instructs GRUB to '''skip parsing <code>grub.cfg</code> and go directly to BLS entries'''.
+This means: ✔ If GRUB was installed '''with BLS enabled''', even if <code>grub.cfg</code> exists, it may not be used.
+✔ If GRUB was installed '''without BLS support''', it will fall back to <code>grub.cfg</code>.
+----
+=='''How to Explicitly Switch Between BLS and <code>grub.cfg</code>'''==
+==='''To Force BLS Mode (and Ignore <code>grub.cfg</code> Completely)'''===
+#'''Ensure BLS entries exist''':  If this folder is empty, something is broken.
+#'''Delete <code>grub.cfg</code>''' (this ensures GRUB won’t use it):
+#'''Ensure GRUB is installed with BLS support''':  ''(For UEFI systems; adjust for BIOS if needed.)''
+#'''Reboot''' and verify that <code>grub.cfg</code> is no longer in use.
+----
+==='''To Force Legacy <code>grub.cfg</code> Mode (and Ignore BLS)'''===
+#'''Ensure <code>grub.cfg</code> is present''':
+#'''Reinstall GRUB to disable BLS mode''':  ''(The <code>--no-bootloader-spec</code> flag explicitly prevents GRUB from using BLS.)''
+#'''Reboot''' and verify that <code>grub.cfg</code> is being used.
+----
+==='''Final Answer'''===
+✔ '''The real switch between BLS and <code>grub.cfg</code> is NOT in <code>/etc/default/grub</code>—it's controlled by how GRUB is installed and configured.'''
+✔ '''Deleting <code>grub.cfg</code> forces BLS mode, provided GRUB was installed with BLS support.'''
+✔ '''Reinstalling GRUB with <code>--no-bootloader-spec</code> forces it to use <code>grub.cfg</code> instead of BLS.'''
+✔ '''To change modes, you must either delete <code>grub.cfg</code> (to force BLS) or reinstall GRUB (to force legacy mode).'''

Modern GRUBing: Difference between revisions