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Why isn't /tmp on that list? I have been using tmpfs for it like forever and I don't see a reason why stuff in /tmp should need to survive a reboot.

The problem here is the space, both /var/lock and /var/run are lightweight directories (less than 1Mb), which is not the case for /tmp : for example, if I download an item with Firefox using the "Open with" option, it's stored in the /tmp, so /tmp can go up to 100Mb or more. I have 6Gb of RAM so it's pointless for me, but for someone with just 512Mb, it is not. Mounting /tmp as tmpfs should be a personal choice. Bouska 16:49, 2 November 2010 (UTC)
+1 for tmpfs /tmp from me. /tmp should be "lightweight" as well, many applications are storing temporary files there, even sensitive stuff which should not go to the disk. At least when the user decides to encrypt her $HOME, /tmp should really be tmpfs by default. The default Firefox download folder is not /tmp but something beneath $HOME. If /tmp is disk-based, it can still fill up and we run out of (disk-)space. Also, Solaris does this for years too (dunno if this is a pro- or con-argument though :-)) -- Ckujau 07:57, 9 March 2011 (UTC)
Also: the "but application xy may fill /tmp and we're running out of space" is true for other world-writable directories too. When /tmp is backed by disk, the disk can be filled up. When it's backed by RAM, the RAM fills up. Even now in F15, a mere user can already (still?) write to /dev/shm thus filling up RAM. -- Ckujau 02:27, 7 August 2011 (UTC)

"...would bring Fedora more inline with the other distributions and minimize differences between the distros." -- Thank you for this! The less needless differences the better.

Part about %ghost directories should be changed according to that means don't \%ghost directories just use tmpfiles.d --plautrba