Jan Alexander Steffens (heftig) authored 3 years ago and Kristian Klausen committed 3 years ago

- Allow killing of any cgroup if swap is about to run out. When swap is
  at least 90% full, oomd will kill a cgroup, tending to kill the cgroup
  with the highest swap usage.
- Allow killing cgroups of logged in users under severe memory pressure.
  When a cgroup is stalled waiting for memory at least 60% of the time,
  for at least 30 seconds, oomd will attempt to kill it or one of its
  descendant cgroups.

It has been applied upstream[1] and released with smartmontools 7.2[2].

[1] https://github.com/smartmontools/smartmontools/commit/61bc85ecadf9e5596b140380fed701a674e38a1b
[2] https://github.com/smartmontools/smartmontools/releases/tag/RELEASE_7_2

This reverts commit b4c97002.

Main motivation behind this is preparing for doing more automatic
upgrades. The need for ignoring kernel updates isn't clear either.

It was removed in:
d9fdafb0 ("Use archlinux-contrib over git submodule")
c380c429 ("Remove old task to symlink checkservices to /usr/local/bin")

Leonidas Spyropoulos authored 3 years ago and Kristian Klausen committed 3 years ago

This is shared between common and install_arch roles

Closed: #288

Signed-off-by: Leonidas Spyropoulos <artafinde@gmail.com>

Benedict Baskar authored 3 years ago and Kristian Klausen committed 3 years ago

Fix #376

Fixes: 678845af ("Add Kape server IPv6 addresses (fixes #230)")

It's been running out of swap during borg-backup and seems to get good
compression ratios; try upping the zram size to 100% of RAM (from 50%).

When both zswap and zram are active, zswap sits in front of zram and
treats it as a backing store. We just want to use zram and not zswap
disguising itself as such; disable the latter so we can enjoy useful
zramctl statistics.

Implemented as tmpfiles.d/zram.conf which disables zswap at runtime.

Restarting swap.target doesn't apply configuration changes; instead we
can restart systemd-zram-setup@zram0 which seems to do what we wanted.

Set "max-zram-size = none" to disable this unwanted limitation which
defaulted to creating zram-based swap with a maximum size of 4096MiB.

Fixes: dc8fa2bd ("common: Replace deprecated systemd-swap[1] with zram-generator")

Without hostname the role does not run.

Kristian Klausen authored 3 years ago and Jelle van der Waa committed 3 years ago

zram-generator defaults to 50% of the ram where systemd-swap defaults to
25% of the ram.

[1] https://lists.archlinux.org/pipermail/arch-dev-public/2021-May/030429.html

Leonidas Spyropoulos authored 3 years ago and Jelle van der Waa committed 3 years ago

Kernel's OOM killer is often too slow, as a result system ends up
thrashing heavily. Have a user-space oom killer helps.

Using default settings as described in
https://www.freedesktop.org/software/systemd/man/oomd.conf.html



Closes: #306

Signed-off-by: Leonidas Spyropoulos <artafinde@gmail.com>

A lot of our systems have a "hardware" watchdog (ex: all the Hetzner
cloud servers) so let's use it.

yaml: truthy value should be one of [false, true] (truthy)
yaml: wrong indentation: expected 4 but found 2 (indentation)
yaml: too few spaces before comment (comments)
yaml: missing starting space in comment (comments)
yaml: too many blank lines (1 > 0) (empty-lines)
yaml: too many spaces after colon (colons)
yaml: comment not indented like content (comments-indentation)
yaml: no new line character at the end of file (new-line-at-end-of-file)
load-failure: Failed to load or parse file
parser-error: couldn't resolve module/action 'hosts'. This often indicates a misspelling, missing collection, or incorrect module path.

It should also be installed before installing any packages with Ansible.

They were apparently controversial and more research is needed.

Do not use asterisk on network devices to prevent IP address collisions
on networks. Also use the right network mask for the assigned network.
For runner1 we need to ignore RAs since those routes don't work.

Kristian Klausen authored 4 years ago and Sven-Hendrik Haase committed 4 years ago

Fix #155

Ansible's hostname supports setting the hostname with hostnamectl, which
makes our systems after the removal of inetutils legacy free.

This is needed for the role to work in containers. The option will also
be applied upstream, see the upstream ticket:
https://github.com/smartmontools/smartmontools/issues/62

Jelle van der Waa authored 4 years ago and Sven-Hendrik Haase committed 4 years ago

Prefer using our maintained version of checkservices from the contrib
repository hosted on our Gitlab repository. This has the benefit of
getting rid of a submodule which isn't cloned by default.

Also set zram_count to 1 because creating 48 devices on dragon is not
usable for swap. We don't need multiple devices anyway; SMP is handled
through multiple compression streams.

This seems way more correct to me as our DNS config is all over the place
and at least this way, we get correct fallback configs right off the bat.

Frederik Schwan authored 4 years ago and Sven-Hendrik Haase committed 4 years ago

also use systemd instead of service module

From dircolors -p