Arch Linux

AndyWM

Member

Registered: 2015-06-10

Posts: 20

Multiple OS boot via bios? (I'd like some verification on my solution)

My PC has multiple drives, Arch is on one, Windows on another. Where to choose I just select the drive from bios.
(It is a UEFI Bios.)

Though, issues arise when both drives are plugged in to the PC together, when I try to boot Arch. It fails, falling into an emergency shell rootfs, claiming to be unable to find root (dev/sda2 for me). rootfs has a directory called, /dev. When I go into that, I see why; sda clearly doesn't have enough partitions to be the drive I installed Arch on (it's now either sdb or sdc)). Whatever happens during this boot sequence also causes Windows, which would otherwise boot fine, if it had been selected first; to hang at boot and eventually go into startup repair, if you reboot a few times.

When I isolate the drives. Windows will boot, Arch will boot. (don't think SATA connectors are designed to be plugged and unplugged as many times as they would be if this is what I do to 'solve' the problem)

I use bootctl as my bootloader. Anything I can do to tell bootctl that the root partition will be sdx2 where x is the drive that it, itself, is on? Or any other suggestions in general would be appreciated.

EDIT:

Checking bootctl it tells me it uses by-partuuid (bootctl status [product: systemd-boot 223 partition: /dev/disk/by-partuuid/some hexademical ...])

Right... So if I label my root partition;

e2label /dev/sda2 archroot

and then go to /boot/loader/entries/arch and change;

options          root=/dev/sda2 rw
to
options          root=/dev/disk/by-label/archroot rw

will the system then be bootable regardless of additional drives?

Last edited by AndyWM (2015-08-18 20:12:49)

karol

Archivist

Registered: 2009-05-06

Posts: 25,440

Re: Multiple OS boot via bios? (I'd like some verification on my solution)

Use UUIDs instead of sda naming.

Edit: https://wiki.archlinux.org/index.php/Un … boot_order ?

Last edited by karol (2015-08-18 18:13:16)

jasonwryan

Anarchist

From: .nz

Registered: 2009-05-09

Posts: 30,426

Website

Re: Multiple OS boot via bios? (I'd like some verification on my solution)

https://wiki.archlinux.org/index.php/Pe … ice_naming

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Arch + dwm   •   Mercurial repos  •   Surfraw

Registered Linux User #482438

AndyWM

Member

Registered: 2015-06-10

Posts: 20

Re: Multiple OS boot via bios? (I'd like some verification on my solution)

In the boot entry. Changing this
options          root=/dev/sda2 rw
to this
options          root=/dev/disk/by-label/archroot rw
didn't harm anything. But it still won't boot if the second drive is plugged in. Worse, I don't even get that ramfs prompt anymore the screen is just black.

Changing that conf is all I have tried implementing. What am I missing? I'm kind of hesitant at doing anything that if not correctly implemented will render the system unbootable...