[gentoo-user] biosdevname or equivalent for disks: did the order change on a specific, recent, kernel version?

[gentoo-user] biosdevname or equivalent for disks: did the order change on a specific, recent, kernel version?

[Larry the Plumber]

Hi!
A bit of history first: my Fedora, then (after reinstall) my openSUSE
then (after reinstall) my Gentoo failed during boot. I thought it was
something related to dracut so I've been adding `hostonly = false` to
dracut.conf on all my home machines.

In summary, yesterday it failed on my Gentoo so I had to investigate.
* I had enable `unstable` use flags for the kernel only.
* I hadn't double-check the boot entries created.
* Power went off (no UPS yet) so I booted the new kernel.
* It didn't boot. I fixed two things: changed the partition id of
LUKSed swap from swap id to LVM id, to prevent systemd attempting to
mount it at boot (and failing). Secondly, I checked the fstab and
noticed all dev nodes were wrong (I have two SSD).
* After fixing the dev nodes in fstab the system booted properly.

This probably explains the Gentoo failure, since other distros (and
me, starting some day) use UUID in fstab.

So, my question is:
Has anyone any input on mysterious failures across several distros,
including Gentoo, around kernel 6.9.x <> 6.10.x?

Re: [gentoo-user] biosdevname or equivalent for disks: did the order change on a specific, recent, kernel version?

[Alan J. Wylie]

Larry the Plumber <dzjfqy7ioz@ol1y.com> writes:

> * It didn't boot. I fixed two things: changed the partition id of
> LUKSed swap from swap id to LVM id, to prevent systemd attempting to
> mount it at boot (and failing). Secondly, I checked the fstab and
> noticed all dev nodes were wrong (I have two SSD).

See
https://lore.kernel.org/lkml/0a43155c-b56d-4f85-bb46-dce2a4e5af59@kernel.org/

| My testlab kernel devel server isn't booting correctly on v6.11
| branches (e.g. net-next at 6.11.0-rc5) I just confirmed this also
| happens on your tree tag: v6.11-rc7.

| The symptom/issue is that harddisk dev names (e.g /dev/sda, /dev/sdb,
| /dev/sdc) gets reordered.  I switched /etc/fstab to use UUID's instead
| (which boots on v6.10) but on 6.11 it still cannot mount harddisks and
| doesn't fully boot.

-- 
Alan J. Wylie                                          https://www.wylie.me.uk/

Dance like no-one's watching. / Encrypt like everyone is.
Security is inversely proportional to convenience

Re: [gentoo-user] biosdevname or equivalent for disks: did the order change on a specific, recent, kernel version?

[Larry the Plumber]

[bottom-posting]

On Wed, Sep 11, 2024 at 2:27 PM Alan J. Wylie <flzdjhmtax@wylie.me.uk> wrote:
>
> Larry the Plumber <dzjfqy7ioz@ol1y.com> writes:
>
> > * It didn't boot. I fixed two things: changed the partition id of
> > LUKSed swap from swap id to LVM id, to prevent systemd attempting to
> > mount it at boot (and failing). Secondly, I checked the fstab and
> > noticed all dev nodes were wrong (I have two SSD).
>
> See
> https://lore.kernel.org/lkml/0a43155c-b56d-4f85-bb46-dce2a4e5af59@kernel.org/
>
> | My testlab kernel devel server isn't booting correctly on v6.11
> | branches (e.g. net-next at 6.11.0-rc5) I just confirmed this also
> | happens on your tree tag: v6.11-rc7.
>
> | The symptom/issue is that harddisk dev names (e.g /dev/sda, /dev/sdb,
> | /dev/sdc) gets reordered.  I switched /etc/fstab to use UUID's instead
> | (which boots on v6.10) but on 6.11 it still cannot mount harddisks and
> | doesn't fully boot.


Hi!
Is it just me or they swapped again? (an unexpected electrical
shutdown gave me further head-scratching)

Thanks,
Larry The Plumber

Re: [gentoo-user] biosdevname or equivalent for disks: did the order change on a specific, recent, kernel version?

[Alan J. Wylie]

Larry the Plumber <dzjfqy7ioz@ol1y.com> writes:

> Is it just me or they swapped again? (an unexpected electrical
> shutdown gave me further head-scratching)

Are you using e.g. "/dev/sda1" in your grub configuration and fstab?

Using UUIDs or block labels on your disks/partitions works around any
randomness in the order in which the kernel sees devices.

e.g.
'''
menuentry 'Linux' {
	echo 'Loading Linux ...'
	search --no-floppy --label --set=root frodoboot
	linux /vmlinuz root=LABEL=frodoroot ro 
	initrd /initramfs.img
}
'''
'''
# blkid /dev/sda1
/dev/sda1: LABEL="frodoboot" UUID="a779e4cf-405e-4e03-a272-e714ba17cd18" BLOCK_SIZE="1024" TYPE="ext4" PARTUUID="de7c8912-01"
'''

https://wiki.gentoo.org/wiki/Handbook:AMD64/Installation/System#Filesystem_information


-- 
Alan J. Wylie                                          https://www.wylie.me.uk/

Dance like no-one's watching. / Encrypt like everyone is.
Security is inversely proportional to convenience