From 69876f94abc3f5861e87ad287b8d1f6770c6fdce Mon Sep 17 00:00:00 2001 From: Chris Down Date: Tue, 9 Jun 2020 14:43:05 +0100 Subject: [PATCH] doc: Try to clarify automount dependency confusion Arch recently upgraded systemd to 245.6. Shortly afterwards, users began reporting[0] that systemd detected an ordering cycle, and they were unable to log in. The reason they were unable to log in was because of ordering cycle resolution: [...] systemd[1]: sysinit.target: Job systemd-tmpfiles-setup.service/start deleted to break ordering cycle starting with sysinit.target/start systemd[1]: sysinit.target: Job systemd-update-done.service/start deleted to break ordering cycle starting with sysinit.target/start systemd[1]: sysinit.target: Job systemd-journal-catalog-update.service/start deleted to break ordering cycle starting with sysinit.target/start systemd[1]: sysinit.target: Job local-fs.target/start deleted to break ordering cycle starting with sysinit.target/start systemd[1]: sysinit.target: Job systemd-tmpfiles-setup.service/start deleted to break ordering cycle starting with sysinit.target/start [...] Whether the resolution did the right thing here or not is a longer-term discussion, but in the interim we should at least make this distinction between automount dependencies and mount dependencies clearer in the documentation, so that users and distribution maintainers know what's acceptable. In this case Arch actually backed out b3d7aef5 entirely and released a new version due to the confusion. Also see https://github.com/systemd/systemd-stable/issues/69. 0: https://bugs.archlinux.org/task/66908 --- man/systemd.automount.xml | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/man/systemd.automount.xml b/man/systemd.automount.xml index 35690fd22a7..fd65f5da798 100644 --- a/man/systemd.automount.xml +++ b/man/systemd.automount.xml @@ -57,6 +57,12 @@ Automount units may be used to implement on-demand mounting as well as parallelized mounting of file systems. + + Note that automount units are separate from the mount itself, so you + should not set After= or Requires= + for mount dependencies here. For example, you should not set + After=network-online.target or similar on network + filesystems. Doing so may result in an ordering cycle.