<div dir="ltr">I had similar problems with a case of booting with the rootfs read-only and then becoming read-write later...<div><br></div><div>Basically systemd only checks for machine-id very early (before reading any config file) and does not deal well with /etc changing status...</div><div><br></div><div>I did a complete analysis of what's going on, with a patch that improves the situation here : <a href="https://github.com/systemd/systemd/pull/14135">https://github.com/systemd/systemd/pull/14135</a></div><div>I am not sure how to deal with it in your specific case. </div><div>the simplest approch would be to mount your overlay in a initrd (or in a small script shell that is run before systemd and exec systemd as its last step)</div><div><br></div><div>My patch wouldn't really help in your case, but maybe you can "cheat" by having the underlying /etc/machine-id bein a symlink to the overlay directory... that could work. </div><div><br></div><div>Regards</div><div>Jeremy</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Le mer. 26 févr. 2020 à 10:59, Andreas Kempe <<a href="mailto:andreas.kempe@actia.se">andreas.kempe@actia.se</a>> a écrit :<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hello everyone,<br>
<br>
I'm working in a project with an embedded Linux system based on<br>
Openembedded using Systemd version 241 as our init process. We're<br>
using a read-only /etc. To facilitate development, we want to use a<br>
writeable overlay on /etc, but we ran into an issue.<br>
<br>
When we start, Systemd detects that there is no machine-id file<br>
present in /etc so it generates and mounts a /etc/machine-id. When our<br>
mount unit then applies the overlay on /etc, it hides the mounted<br>
file. Journald later fails to start because /etc/machine-id isn't<br>
visible through the overlay.<br>
<br>
At this point we're considering a number of workarounds, but I thought<br>
it worthwhile asking the experts before we go patching Systemd or<br>
similar.<br>
<br>
My gut feeling is that using overlays on /etc can't be that uncommon<br>
and it is likely PEBKAC on our end. Is there some canonical way of<br>
doing overlays with Systemd and we're screwing things up?<br>
<br>
Thank you in advance for any help!<br>
Cordially,<br>
Andreas Kempe<br>
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</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><table border="0" style="border-collapse:collapse;border-spacing:0px;color:rgb(51,51,51);font-family:Raleway,regular;font-size:14px;padding:20px"><tbody><tr><td style="padding:0px 30px 0px 0px;font-size:13px;color:rgb(255,128,84);text-align:center"><a href="http://www.smile.eu/" style="background-color:transparent;color:rgb(221,72,20)" target="_blank"><img src="http://ftp.smile.fr/client/Communication/signature/img/Logo-new.png" alt="SMILE" style="border: 0px; vertical-align: middle; max-width: 100%; height: auto;"> </a><br><br><p style="margin:0px 0px 10px">20 rue des Jardins<br>92600 Asnières-sur-Seine</p></td><td style="padding:0px 0px 0px 20px;border-left:1px solid rgb(59,127,254);font-size:13px;color:rgb(255,128,84)"><div style="font-size:14px"><b>Jérémy ROSEN</b></div><div style="color:rgb(59,127,254)">Architecte technique<br></div><br><div style="color:rgb(59,127,254)"><span style="white-space:nowrap"><img src="http://ftp.smile.fr/client/Communication/signature/img/mail.png" alt="email" width="12" height="10" style="border: 0px; vertical-align: middle; margin-right: 5px;"> <a href="mailto:jeremy.rosen@smile.fr" style="background-color:transparent;color:rgb(59,127,254)" target="_blank">jeremy.rosen@smile.fr</a> </span><br><span style="white-space:nowrap"><img src="http://ftp.smile.fr/client/Communication/signature/img/phone.png" alt="phone" width="10" height="10" style="border: 0px; vertical-align: middle; margin-right: 5px;"></span> +33 6 88 25 87 42 <br><span style="white-space:nowrap"><img src="http://ftp.smile.fr/client/Communication/signature/img/web.png" alt="url" width="12" height="12" style="border: 0px; vertical-align: middle; margin-right: 5px;"> <a href="http://www.smile.eu/" style="background-color:transparent;color:rgb(59,127,254)" target="_blank">http://www.smile.eu</a></span></div><br><div><span><a href="https://twitter.com/GroupeSmile" style="background-color:transparent;color:rgb(221,72,20);margin-right:5px" target="_blank"><img src="http://ftp.smile.fr/client/Communication/signature/img/rs-twitter.png" alt="Twitter" style="border: 0px; vertical-align: middle; max-width: 100%; height: auto;"></a></span> <span><a href="https://www.facebook.com/smileopensource" style="background-color:transparent;color:rgb(221,72,20);margin-right:5px" target="_blank"><img src="http://ftp.smile.fr/client/Communication/signature/img/rs-facebook.png" alt="Facebook" style="border: 0px; vertical-align: middle; max-width: 100%; height: auto;"></a></span> <span><a href="https://www.linkedin.com/company/smile" style="background-color:transparent;color:rgb(221,72,20);margin-right:5px" target="_blank"><img src="http://ftp.smile.fr/client/Communication/signature/img/rs-linkedin.png" alt="LinkedIn" style="border: 0px; vertical-align: middle; max-width: 100%; height: auto;"></a></span> <span><a href="https://github.com/Smile-SA" style="background-color:transparent;color:rgb(221,72,20);margin-right:5px" target="_blank"><img src="http://ftp.smile.fr/client/Communication/signature/img/rs-github.png" alt="Github" style="border: 0px; vertical-align: middle; max-width: 100%; height: auto;"></a></span></div></td></tr></tbody></table><br style="color:rgb(51,51,51);font-family:Raleway,regular;font-size:14px"><div style="color:rgb(51,51,51);font-family:Raleway,regular;font-size:14px"><a href="https://www.smile.eu/fr/publications/livres-blancs/yocto?utm_source=signature&utm_medium=email&utm_campaign=signature" style="background-color:transparent;color:rgb(221,72,20)" target="_blank"><img src="https://signature.smile.eu/assets/img/bandeaux_signature_mail_yocto.gif.gif" alt="Découvrez l’univers Smile, rendez-vous sur smile.eu" border="0" style="border: 0px; vertical-align: middle;"></a></div></div></div></div></div>