So, the root cause is completely clear: dbus.socket starts early, then cloud-init starts which blocks the entire basic.target (early boot) on network operations, thus dbus.service cannot start. nss-resolve already sees dbus.socket and thus can connect (instead of failing fast), and then gets the 25s D-Bus timeout as D-Bus is blocked.
- Moving dbus.service into early boot would be a bold step, and I don't think such a large change is appropriate two weeks before release. - Rearranging nsswitch.conf and modify it on the fly also sounds like a big no. - I'd also not like to generally move dbus.socket into late boot, as that would break other services during early boot which queue up a connection to D-Bus. - So far the cleanest way out of this would be to also make dbus.socket wait for cloud-init.service, as that already blocks dbus.service. I verified that name resolution is then fast again. This also doesn't cause dependency loops as both cloud-init.service and sockets.target run in early boot. Could you try adding "Before=dbus.socket" to /lib/systemd/system/cloud- init.service and confirm that this helps? (Does for me in a container, but I don't have access to GCE or EC2) -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1629797 Title: resolve service in nsswitch.conf adds 25 seconds to failed lookups before systemd-resolved is up Status in cloud-init package in Ubuntu: Invalid Status in systemd package in Ubuntu: Triaged Bug description: During boot, cloud-init does DNS resolution checks to if particular metadata services are available (in order to determine which cloud it is running on). These checks happen before systemd-resolved is up[0] and if they resolve unsuccessfully they take 25 seconds to complete. This has substantial impact on boot time in all contexts, because cloud-init attempts to resolve three known-invalid addresses ("does- not-exist.example.com.", "example.invalid." and a random string) to enable it to detect when it's running in an environment where a DNS server will always return some sort of redirect. As such, we're talking a minimum impact of 75 seconds in all environments. This increases when cloud-init is configured to check for multiple environments. This means that yakkety is consistently taking 2-3 minutes to boot on EC2 and GCE, compared to the ~30 seconds of the first boot and ~10 seconds thereafter in xenial. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1629797/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
