Re: [gentoo-user] systemd mount - what on earth is it doing ...

[Canek Peláez Valdés]

On Sat, Sep 25, 2021 at 1:48 PM antlists <antlists@××××××××××××.uk> wrote:
[...]

> Bear in mind, integritysetup is not in my initrd, so ...
>

I think you would need to put it in your initrd.


> It looks to me like grub switches to the real root partition read-only
> before firing stuff off, so if I tell my integritysetup.service to run
> before local-fs.target, does that mean everything should be working
> before systemd runs fstab?
>
> Bear in mind dm-integrity is on my raw partitions, and I'm running lvm
> and md-raid, I'm guessing they're part of local-fs-pre.target? So I
> really need to run dm-integrity before that? Or preferably add
> dm-integrity TO that - how do I do that?
>
> The problem is this isn't all that discoverable - even digging around
> /etc/systemd, it's hard to find clues ...
>

As Rich already mentioned it, noauto != remove mount point from fstab.
That's the first thing.

Then you need to specify that home.mount should run *after* md/LVM, which
in turn runs after your integrity setup service. The problem is: you have
root (/) on md/LVM too; I know they are different RAIDs/volumes, but there
is one *service* for RAID and LVM, at least out-of-the-box, in systemd. You
could try to split different instances using templates (the units with @ in
their names), but the simplest solution is to put your integrity logic in
the initrd (with the added benefit that you can mount it in emergencies if
something goes wrong with root).

If you have the integrity logic in early boot, then your integrity setup
service should have:

Before=mdmonitor.service lvm2-lvmetad.service

And I think that should be enough? The home.mount unit depends on the
underlying device being available, and that will happen only after md and
LVM have done it's thing.

Regards.
--
Dr. Canek Peláez Valdés
Profesor de Carrera Asociado C
Departamento de Matemáticas
Facultad de Ciencias
Universidad Nacional Autónoma de México