On Tue, Jun 1, 2021 at 1:09 PM Mantas Mikulėnas <graw...@gmail.com> wrote: > > If it's not writable at that point, systemd will *mount* a temporary writable > file on top of it, and will generate an ID that's temporary for that boot.
I've ended up copying /etc/machine-id onto our overlay etc directory before mounting the actual overlay, this way after mounting /etc the machine also persists across reboots. I think systemd still regenerates the machine-id on boot because the overlay isn't mounted yet, so a more long term solution would be to use an initramfs to mount the overlay before system starts (unless there are other ways to do so). > > It's possible that your overlay goes on top of that and provides its own > empty machine-id file again... > >> Make our overlay mount unit depend on whatever service is generating >> machine-id and make sure our mount happens before the generation of >> machine-id? > > > That might work, and would allow the machine-id and thus the DUID to be > persistent. > > As an alternative you could tell networkd to use DUID-LLT (?), which doesn't > need the machine-id and just uses the MAC address, but there may be other > things which use the machine-id anyway... > >> >> Thanks >> >> -- >> Alessandro Tagliapietra >> >> >> On Tue, Jun 1, 2021 at 12:13 AM Mantas Mikulėnas <graw...@gmail.com> wrote: >>> >>> On Tue, Jun 1, 2021 at 10:07 AM Alessandro Tagliapietra >>> <tagliapietra.alessan...@gmail.com> wrote: >>>> >>>> Hello everyone, >>>> >>>> I'm using yocto to create a custom linux image for a raspberry pi. >>>> We have an "agent" that writes /etc/systemd/network/20-eth.network when >>>> the final user wants to have a static IP address and we remove the file >>>> when they switch back to DHCP. >>>> >>>> After creating/deleting the file above we run `networkctl reload && >>>> networkctl reconfigure eth0`. >>>> We mount the overlayfs with a custom .mount unit. >>>> >>>> We've noticed that DHCP works fine if systemd-networkd starts before we >>>> mount the overlayfs but it doesn't if systemd-networkd is >>>> restarted/reconfigured after the folder is mounted or started after the >>>> overlay .mount unit. >>>> >>>> Every interface DHCP fails with: >>>> >>>> DHCPv6 CLIENT: Failed to set DUID-EN: No medium found >>>> eth0: DHCP6 CLIENT: Failed to set DUID: No medium found >>> >>> >>> My guess is that it's related to /etc/machine-id somehow becoming >>> inaccessible, since networkd's DUID-EN (DUIDType=vendor) is based on that. >>> >>> -- >>> Mantas Mikulėnas _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
