Arch Linux

Many things changed since this request was first opened, the original problems are solved elsewhere, but there are still reasons to implement this:

The new tmpfs-mounted /run folder allows programs like udev, lvm and mdadm to keep runtime data from initrd until shutdown.

We can move all runtime data to these folders by simply creating symlinks in /var. In addition to consolidating all the runtime data in one place, this will remove needless writes to disk, as well as remove the need to cleanup the directories on boot.

Implementing this is still blocked by packages that (mistakenly) rely on data in /var/{run,lock} being persistent after reboot (as described below).

Original feature request:
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In another bug report, I got the impression that mounting tmpfs for /var/run and /var/lock very early in the initialization process is a good idea and solves some stupid problems when running applications while /var is still readonly.

Problems:

1) People might have /var on a separate partition from /
2) Some programs don't work if their /var/{run,lock}/whatever folder is missing - I would consider these bugs, but we need to think about it. We would also have to stop putting /var/{lock,run}/* files or directories into packages. On my system:
$ grep -e ^var/run -e ^var/lock /var/lib/pacman/local/*/files | cut -d: -f2|sort -u
var/lock/
var/lock/sane/
var/run/
var/run/bftpd/
var/run/ConsoleKit/
var/run/dbus/
var/run/hald/
var/run/hald/hald-local/
var/run/hald/hald-runner/
var/run/httpd/
var/run/lirc/
var/run/mpd/
var/run/mysqld/
var/run/network/
var/run/network/interfaces/
var/run/network/profiles/
var/run/openntpd/
var/run/PolicyKit/
var/run/samba/

I assigned a few people to this who might have an opinion and useful input here, feel free to remove yourself if you don't care.