[Bug 2019026] Re: systemd /tmp cleaning is suboptimal

[Brian Murray]

The Ubuntu QA team encountered an issue where our autopkgtest-cloud-
workers in the prod-proposed-migration environment ran out of free space
in /tmp because these are production servers which are rebooted very
infrequently. Due to some bug in the autopkgtest-cloud or autopkgtest
code there were left over log files from late November, December, and
January in /tmp. These log files can be quite large and our 200G /tmp
partition ended up being full quite regularly.

I too would expect /tmp to be cleaned up regularly and remember the days
when it was.

It be interesting to see what other server administrators do about
cleaning up /tmp. Does everyone modify /usr/lib/tmpfiles.d/tmp.conf ?

** Changed in: systemd (Ubuntu)
       Status: New => Confirmed

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/2019026

Title:
  systemd /tmp cleaning is suboptimal

Status in systemd package in Ubuntu:
  Confirmed

Bug description:
  Historically on Debian and Ubuntu, before systemd, the default
  handling of /tmp was to periodically, and at boot, remove all
  files/directories older than 30 days; and leave other contents alone.

  With the move to systemd, the "default" (really, hard-coded in
  /usr/lib/tmpfiles.d/tmp.conf) is to not clean /tmp periodically, but
  at boot to remove all contents.

  This is suboptimal for two reasons.

  By cleaning /tmp *only* at boot, if a system makes heavy use of /tmp
  and has lots of inodes under it, possibly due to failures of some
  process to clean up after itself, at boot the system will be
  unavailable for an unnecessarily long time while these files are
  removed.

  By cleaning *all* files under /tmp, this makes a reboot an Event where
  in-progress files may be unnecessarily lost.

  While the FHS does not *guarantee* that files under /tmp will persist
  across boot (because /tmp may be a tmpfs), it also does not *require*
  that /tmp be cleared on boot.

     Although data stored in /tmp may be deleted in a site-specific
     manner, it is recommended that files and directories located in
     /tmp be deleted whenever the system is booted.

     FHS added this recommendation on the basis of historical
     precedent and common practice, but did not make it a
     requirement because system administration is not within the
     scope of this standard.

  I therefore believe the correct value for /usr/lib/tmpfiles.d/tmp.conf
  to restore past behavior is 'd /tmp 1777 root root 30d'.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/2019026/+subscriptions