Thanks. I checked the second affected host (smb5) in more detail. The installed generators are:
/usr/lib/systemd/system-generators/cloud-init-generator -> cloud-init /usr/lib/systemd/system-generators/netplan -> netplan-generator /usr/lib/systemd/system-generators/postfix-instance-generator -> postfix /usr/lib/systemd/system-generators/rpc-pipefs-generator -> nfs-common /usr/lib/systemd/system-generators/snapd-generator -> snapd /usr/lib/systemd/system-generators/sshd-socket-generator -> openssh-server /usr/lib/systemd/system-generators/systemd-*-generator -> systemd /etc/systemd/system-generators only contains: systemd-gpt-auto-generator -> /dev/null /run/systemd/system-generators does not exist. For the unattended-upgrades run immediately preceding the fatal daemon- reexec on 2026-09-03, the package list was: libevent-2.1-7t64 libevent-core-2.1-7t64 libevent-pthreads-2.1-7t64 libgcrypt20 libncurses-dev libncurses6 libncursesw6 libtinfo6 ncurses-base ncurses-bin ncurses-term python3-pyasn1 None of the packages providing the systemd generators were upgraded in that run. The sequence was: 06:21:41 unattended-upgrades started 06:22:11 daemon-reexec requested 06:22:12 systemd reexec completed 06:23:42 Failed to fork off sandboxing environment for executing generators: Protocol error 06:23:42 Freezing execution So again almost exactly 90 seconds. I also checked the older logs and found that this was NOT the first occurrence on smb5. There were already similar generator sandbox failures before September 3, for example: 2026-09-01 06:25:09 Reloading requested ... 2026-09-01 06:26:39 Failed to fork off sandboxing environment for executing generators: Protocol error and additional occurrences later on September 1, as well as on August 29. This makes it less likely that one package updated in the September 3 unattended-upgrades run introduced the problem. If useful, I can collect older package histories around the first occurrence and/or test the generators individually on a test VM. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2165295 Title: systemd freezes after daemon-reexec triggered by unattended-upgrades / needrestart on Ubuntu 24.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/2165295/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
