Arch Linux

kaffeekind

Member

Registered: 2022-05-04

Posts: 8

Two arch installations

For work in home office, I want to have a second arch installation (that's on an encrypted drive). My setup is:
Fun arch installation:
nvme0n1p1: boot
nvme0n1p2: root
Work installation:
sdb1: boot
sdb2: root

So right now I have to configured grub bootloader. None of them detect the other one. I don't really have a clue how to lay out these. I once tried to install the second arch installation with the same boot partition, but then I got name clashes.
My problem is that I can't really find anything, cause I only get results for sth like dual boot with windows.

What is the general setup here? Partition and folder layout? Do I need to manually create folder, rename files? Feels weird, so I wanted to ask.

cryptearth

Member

Registered: 2024-02-03

Posts: 1,928

Re: Two arch installations

well - having both systems not find eachother I would see as a benefit for such a setup and rely on uefi boot selector as intented by uefi

if you want to stick to grub: in one of the setups install os-prober and uncomment last line in /etc/default/grub

kaffeekind

Member

Registered: 2022-05-04

Posts: 8

Re: Two arch installations

well - having both systems not find eachother I would see as a benefit for such a setup and rely on uefi boot selector as intented by uefi

if you want to stick to grub: in one of the setups install os-prober and uncomment last line in /etc/default/grub

Sorry, I though I wrote that already. I disabled the disabling of osprober in the config and os-prober is installed. Nothing is detected.

Why is a uefi boot selector here preferred? It sucks to spam F11 every time. This is not different than dual booting with windows only that it's two arch systems. But the intended workflow stays the same. This seems unnecessarily hard.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,017

Re: Two arch installations

You need to mount the partition containing the boot files (vmlinuz-linux and initramfs-linux.img) before os-prober can generally detect anything (it doesn't inherently matter where you mount it, but os-prober generally looks at the mtab first and foremost to find entries to generate), did you do that before running grub-mkconfig?

kaffeekind

Member

Registered: 2022-05-04

Posts: 8

Re: Two arch installations

You need to mount the partition containing the boot files (vmlinuz-linux and initramfs-linux.img) before os-prober can generally detect anything (it doesn't inherently matter where you mount it, but os-prober generally looks at the mtab first and foremost to find entries to generate), did you do that before running grub-mkconfig?

Actually didn't do that. So I mounted the other boot partition to /mnt and executed

grub-mkconfig -o /boot/grub/grub.cfg

again. I didn't recognize any results in the output indicating a success (it showed that it looked for other systems with os-prober) and after reboot I still only have the one Arch Linux entry.

Last edited by kaffeekind (2026-01-26 17:43:03)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,017

Re: Two arch installations

Post your outputs of

mount
ls -lR /boot /mnt
grub-mkconfig -o /boot/grub/grub.cfg
cat /boot/grub/grub.cfg
efibootmgr -uv

while having setup the situation that os-prober should work (alternatively you can alter the grub.cfg yourself and add the necessary entries by hand) Is there anything special about the "other" /boot partition (is it encrypted as well?)

kaffeekind

Member

Registered: 2022-05-04

Posts: 8

Re: Two arch installations

mount:

/dev/mapper/root on / type btrfs (rw,relatime,ssd,space_cache=v2,subvolid=256,subvol=/@)
devtmpfs on /dev type devtmpfs (rw,nosuid,size=15888720k,nr_inodes=3972180,mode=755,inode64)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,inode64,usrquota)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=600,ptmxmode=000)
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
cgroup2 on /sys/fs/cgroup type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot,memory_hugetlb_accounting)
none on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
efivarfs on /sys/firmware/efi/efivars type efivarfs (rw,nosuid,nodev,noexec,relatime)
bpf on /sys/fs/bpf type bpf (rw,nosuid,nodev,noexec,relatime,mode=700)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
tmpfs on /run type tmpfs (rw,nosuid,nodev,size=6388260k,nr_inodes=819200,mode=755,inode64)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=40,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=10705)
debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime)
tracefs on /sys/kernel/tracing type tracefs (rw,nosuid,nodev,noexec,relatime)
mqueue on /dev/mqueue type mqueue (rw,nosuid,nodev,noexec,relatime)
configfs on /sys/kernel/config type configfs (rw,nosuid,nodev,noexec,relatime)
fusectl on /sys/fs/fuse/connections type fusectl (rw,nosuid,nodev,noexec,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,nosuid,nodev,relatime,pagesize=2M)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev,nr_inodes=1048576,inode64,usrquota)
none on /run/credentials/systemd-journald.service type tmpfs (ro,nosuid,nodev,noexec,relatime,nosymfollow,size=1024k,nr_inodes=1024,mode=700,inode64,noswap)
/dev/sdb1 on /boot type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro)
tmpfs on /run/user/1000 type tmpfs (rw,nosuid,nodev,relatime,size=3194128k,nr_inodes=798532,mode=700,uid=1000,gid=1000,inode64)
portal on /run/user/1000/doc type fuse.portal (rw,nosuid,nodev,relatime,user_id=1000,group_id=1000)
/dev/nvme0n1p1 on /mnt type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro)

ls -lR /boot /mnt

grub-mkconfig -o /boot/grub/grub.cfg:

Generating grub configuration file ...
Found linux image: /boot/vmlinuz-linux
Found initrd image: /boot/amd-ucode.img /boot/initramfs-linux.img
Warning: os-prober will be executed to detect other bootable partitions.
Its output will be used to detect bootable binaries on them and create new boot entries.
Adding boot menu entry for UEFI Firmware Settings ...
done

cat /boot/grub/grub.cfg

efibootmgr -uv:

BootCurrent: 0002
Timeout: 1 seconds
BootOrder: 0002,0000,0003,0004,0005
Boot0000* GRUB	HD(1,GPT,7679671d-73d5-4f28-a6f9-053062d28287,0x800,0x200000)/\EFI\GRUB\grubx64.efi
      dp: 04 01 2a 00 01 00 00 00 00 08 00 00 00 00 00 00 00 00 20 00 00 00 00 00 1d 67 79 76 d5 73 28 4f a6 f9 05 30 62 d2 82 87 02 02 / 04 04 30 00 5c 00 45 00 46 00 49 00 5c 00 47 00 52 00 55 00 42 00 5c 00 67 00 72 00 75 00 62 00 78 00 36 00 34 00 2e 00 65 00 66 00 69 00 00 00 / 7f ff 04 00
Boot0002* GRUB2	HD(1,GPT,37a04f41-c978-4b98-b673-6f227c38a05e,0x800,0x200000)/\EFI\GRUB2\grubx64.efi
      dp: 04 01 2a 00 01 00 00 00 00 08 00 00 00 00 00 00 00 00 20 00 00 00 00 00 41 4f a0 37 78 c9 98 4b b6 73 6f 22 7c 38 a0 5e 02 02 / 04 04 32 00 5c 00 45 00 46 00 49 00 5c 00 47 00 52 00 55 00 42 00 32 00 5c 00 67 00 72 00 75 00 62 00 78 00 36 00 34 00 2e 00 65 00 66 00 69 00 00 00 / 7f ff 04 00
Boot0003* UEFI:CD/DVD Drive	BBS(129,,0x0)
      dp: 05 01 09 00 81 00 00 00 00 / 7f ff 04 00
Boot0004* UEFI:Removable Device	BBS(130,,0x0)
      dp: 05 01 09 00 82 00 00 00 00 / 7f ff 04 00
Boot0005* UEFI:Network Device	BBS(131,,0x0)
      dp: 05 01 09 00 83 00 00 00 00 / 7f ff 04 00