Debian Developer Luca Boccassi announced the transition of Debian to use tmpfs in /tmp and to clean /tmp and /var/tmp on a timer by default, starting with Debian 13 “Trixie.”
In new systems, files in /tmp will either disappear with the previous tmpfs instance in memory after a restart or will be deleted daily on a timer if they are older than 10 days, while files in /var/tmp will only be deleted daily on a timer if they are older than 30 days. The openssh and tmux packages have been modified to retain their temporary files in /var/tmp as an exception. In systems upgrading to Debian 13 “Trixie,” the old behavior of /var/tmp will remain.
While most other distributions have long switched to using tmpfs in /tmp, Debian has been slow to do so. Now, Debian developers (Michael Biebl and Luca Boccassi) have resumed a discussion from 2020, where a developer from Canonical (Eric Desrochers) complained about the inconsistency of the then-implementation of /var/tmp in Debian with how systemd works, despite a patch being published back in 2012. Thus, it was decided to align the system's behavior regarding these directories with the norms in systemd and in most other distributions.
Source: linux.org.ru
