[systemd-devel] Using btrfs subvolumes with systemd

[Florent Peterschmitt]

10 juin 2016 18:26 "Lennart Poettering" <lennart at poettering.net> a écrit:
> On Fri, 10.06.16 13:48, Florent Peterschmitt (florent at peterschmitt.fr) wrote:
> 
>> I have no udev rules at all in this initramfs, and as I said in
>> another mail, i'll try with genkernel-next that embeds udev (there is
>> a specific option for that) and do stuff with SYSTEMD_READY.
> 
> I am not sure DM is capable of initializing first without udev and
> then with.
> 
> The other code should be fine though, i.e. normally "udev trigger" is
> all that's necessary to make devices appear. It's just that DM is a
> bit weird...
> 
> Lennart
> 
> --
> Lennart Poettering, Red Hat

Well, using dracut with crypt, systemd and btrfs modules (among others) works just fine.

The genkernel-next scripts weren't setting SYSTEMD_READY=1 anywhere, only SYSTEMD_READY=0… and for crypt devices apparently.

dracut has a udev rule that set ENV{SYSTEMD_READY}=1

I guess I should build my own initrd to learn precisely how it works.

Florent Peterschmitt