This service is essentially a random sleep() call that old software that
is unable to properly handle modern hardware initialisation being
asynchronous can use to *mostly* get by.
Over the years is has caused so many issues in NixOS, like introducing
long delays in the boot process[1], complete deadlocks[2] and even failures
when reloading services or activating a new configuration[3].
systemd has been discouraging its use since 2011 (15 years ago!), then
it officially deprecated it in 2018 and since 2020 it started to show on
every boot a huge wall of text calling out all the offending services
that still use it.
Around 2021 we managed to fix around 15 NixOS modules[4] that were
relying on systemd-udev-settle and practically ZFS[5] was the only
remaining one. However, since then, people have actually started to
bring it back with new services[6][7][8]. This is not acceptable.
So, to prevent any more (lazy) uses of systemd-udev-settle, we stop
providing the systemd-udev-settle.service unit entirely. For existing
modules that unfortunately still need it, we replace it with the command
`udevadm settle --timeout=180`, which is all that the service does.
Hopefully this will also increase the awareness that it's bad and
something to be fixed.
Note: I tested this change using
- `nixosTests.zfs`,
- `nixosTests.ifstate`,
- `nixosTests.misc`,
- `nixosTests.openvswitch`,
- `nixosTests.predictable-interface-names`
- `nixosTests.nvidia-container-toolkit`
and making sure that none of the 165 packages that provide upstream
units (via the `systemd.packages` option) had a dependency on
systemd-udev-settle.service.
[1]: https://github.com/NixOS/nixpkgs/pull/25311
[2]: https://github.com/NixOS/nixpkgs/issues/107341
[3]: https://github.com/NixOS/nixpkgs/pull/113804
[4]: https://github.com/NixOS/nixpkgs/issues/73095
[5]: https://github.com/openzfs/zfs/issues/10891
[6]: https://github.com/NixOS/nixpkgs/pull/257525#discussion_r1442702970
[7]: https://github.com/NixOS/nixpkgs/pull/460075
[8]: https://github.com/NixOS/nixpkgs/pull/284507
The nix module uses tmpfiles, not the other way around.
Move definitions so that tmpfiles does not depend on the nix module.
This makes the tmpfiles module usable without loading a nix module.
journald.nix had mkRenamedOptionModule from enableHttpGateway to
services.journald.gateway.enable. Move it to journald-gateway.nix
where the target option is defined.
stage-1.nix had mkRenamedOptionModule from boot.initrd.mdadmConf to
boot.swraid.mdadmConf. Move it to tasks/swraid.nix where the target
option is defined.
Upstream systemd changed how modprobe is discovered. It is now searched
for on path. Thus, add the kmod package to the ExecSearchPath of the
modprobe@.service.
NixOS has traditionally enabled the `ext` family of file systems by
default. Originally, when switching to systemd initrd, we wanted to
transition to making this explicit so that initrds could be made
without `ext`. The problem is that anyone with `fsType = "auto";` for
an `ext` file system in initrd will fail to boot, which is not really
an acceptable regression as we switch to systemd initrd by default.
By removing `default = "auto"` from `fsType`, we rule out the vast
majority of these regressions as eval errors, since most users of
`fsType = "auto"` for ext file systems are using it because of the
default value.
In hindsight, this is probably what #225352 was really about.
Move the portable modular service base from
nixos/modules/system/service/portable/ to lib/services/, making it
importable by any module system (home-manager, nix-darwin) without
reaching into the nixos/ tree.
Moved files: service.nix, lib.nix, config-data.nix, config-data-item.nix,
test.nix. All external references updated (systemd/system.nix,
doc/manual/default.nix, assertions.nix, README.md).
No functional changes - only import paths differ.
With kernel versions at 7.0 or greater, `aes_generic` no longer exists
and is now just called `aes`. The `aes` module alias has existed since
at least 5.10 (the oldest kernel currently in nixpkgs), so is sufficient
to load `aes_generic` on older kernels.
With kernel versions at 7.0 or greater, `aes_generic` no longer exists
and is now just called `aes`. The `aes` module alias has existed since
at least 5.10 (the oldest kernel currently in nixpkgs), so is sufficient
to load `aes_generic` on older kernels.
