First I apologise, as I guess I could find some answers on Manjaro or Arch wikis. I’ll browse them later, when I have more time.
I’m a 6 months old Linux recruit, some topics are still shady for me. I had first Cinnamon installed, with separate partitions for Data and Backup. Then I scratched my system and put KDE instead, with separate partitions for boot, swap, root and home. As Data and Backup were created first, they’re still sda3 and sda4, while my root is sda8 even if the partition is placed before… Well, that’ll be for another day.
I wanted to try Manjaro Gnome outside Virtualbox, so I reduced my Data partition and installed it in manual fashion in Calamares, with same as KDE, boot, swap, root and home partitions above the unallocated space.
At reboot I got an ugly vanilla Linux grub instead of Manjaro’s and the 1st entry was Gnome and no more KDE. Gnome booted OK, and when I selected KDE, I got initramfs missing then kernel panic
Hopefully booting with 5.8 fallback worked. I tried
update-grub, got nothing better than vmlinuz not found and still that old school grub. Maybe I tried other forgotten commands during the panic. Until
grub-install put an end to my misery and reverted all to normal with Manjaro grub, KDE first. But Gnome this time would go initramfs missing too and only worked with fallback.
Deleted Gnome, I then put the empty space back to Data and chose this time in Calamares to install alongside and make it shrink automatically the partition (and get root, home, in a same partition).
Bim, still the ugly grub and fallback for KDE.
install-grub again to revert but this time, Gnome works directly when selected in boot menu.
So I have all I wanted but don’t get all what did go wrong. And more, what I did wrong (who said ALL? )
How could I have installed a 2nd Manjaro without breaking my 1st? Would have it be possible to select a manual partitioning (and splitting root, home, …) during install as I first tried AND succeed?
And if I already get a swap and a boot partition for my KDE, do I need that also for my Gnome? (yes I know I could use a swap file instead) Or will these be shared between the 2?
And last, I edited my Gnome
/etc/default/grub and removed quiet. I updated grub but its still all black at boot and at shutdown/reboot. How do I see all the systemd logs as I have in KDE?
Ah a last one, would tweaking mkinitcpio be helping in my case? Or is it irrelevant here?