Greg Wooledge composed on 2025-12-28 12:14 (UTC-0500):
> 9) Every time you install a new kernel or need a new initrd image to
> be used in any of your OSes (firmware updates, microcode, etc.),
> you'll need to boot into the "master" OS and re-run update-grub.
/etc/grub.d/ contains files 40_custom and 41_custom. 41_custom causes
/boot/grub/custom.cfg's content, if admin has caused its existence, to be
included
in the Grub menu presented when booting. Edits to it take effect immediately,
that
is, whatever in it that is valid will be contained in the tail of the Grub menu.
If 41_custom is copied or renamed to e.g. 07_custom, its valid stanzas will
precede auto-generated Grub stanzas in the boot menu (instead, if 41_custom is
deleted or emptied; in addition to those at the end if merely copied).
40_custom is for containing admin-prepared stanzas for Grub to include in
/boot/grub/grub.cfg, roughly equivalent to using 41_custom and custom.cfg, but
needing updating of grub.cfg after editing to take effect.
Utilizing either of these two files offers the admin the opportunity for minimal
Grub multiboot config maintenance, because their stanzas can utilize the
non-versioned kernel and initrd symlinks Debian and some other distros include
in
/, some distros include in /boot/, and admin may create or have created anywhere
readable by Grub during boot. Maintenance of 40_custom or custom.cfg normally is
only required when command line parameters in stanzas are to be
added/removed/modified, or a bootable distro is added or removed from the
system.
Either of these optional Grub stanza maintenance methods can obviate need for
os-prober.
> [*] If you allow the installer to touch your swap partition, for example,
> it will probably recreate it from scratch, with a new UUID, and this
> will invalidate all the swap UUIDs in all of your other fstab files.
> That's why I recommend manually adding it to all your fstab files.
During installation of other than master, simply ensure no swap state - neither
using existing nor creating swap. When creating swap, give it a LABEL, and mount
it by LABEL in the fstabs post-installation. If accident happens to change
swap's
LABEL, it can be recreated with same LABEL, thus, requiring no fstab editing
after
the initial or accident.
--
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
