I have been using tmpfs for /tmp and /var/tmp for years and years on my gentoo system. Why is this such a big deal?
Phoronix: Fedora 18 Will Go For Tmpfs
Fedora 18 will look to use tmpfs for its /tmp directory, after the feature proposal was approved today by the Fedora Engineering and Steering Committee...
http://www.phoronix.com/vr.php?view=MTA4MTg
I have been using tmpfs for /tmp and /var/tmp for years and years on my gentoo system. Why is this such a big deal?
It's not really a big deal if your individual user configuration uses tmpfs, but it's a big deal for huge (general purpose) distros. They have to take into account the amount of RAM their users have and maybe change their minimum spec requirements (could cause outrage). And even if we can assume that all users have 6Gb of RAM, we'll still have to consider their workloads. For example, I have /var/tmp/portage as tmpfs, but neither libreoffice nor chromium will compile because they're so huge. Granted, the portage problem is easily fixed, but this is Gentoo, and it's meant to be tweaked heavily.
The other distros don't have it so easy. They must "please everyone" or die trying.
"Do NOT use it on /var/tmp, because that folder is meant for temporary files that are preserved across reboots. " https://wiki.archlinux.org/index.php/Fstab
tmpfs can (and probably will) go to swap as well, which should still perform better than a real on-disk FS. As long as there's enough swap available, running out of memory shouldn't be an issue, or cause slow-downs.
Oh, and as long as you set your /var/tmp/portage-tmpfs to >6GB and have enough swap, libreoffice will compile fine, without slowing down your machine more than running it on a real FS.
As for putting /var/tmp on a tmpfs: aufs it with a squashfs that you auto-recreate once in a while, including during shutdown. Best of both worlds (apart from losing your temporary data in-between the last recreation and a crash/power-failure...), plus it's now compressed.
I have had /tmp, /var/tmp and /var/log on tmpfs on my laptop (with an SSD that doesn't do trim) for years running ubuntu. I know /var/tmp should be persistant, but on my laptop, I just didn't care enough
Though I appreciate the link, I think the FHS should be the correct link"Do NOT use it on /var/tmp, because that folder is meant for temporary files that are preserved across reboots. " https://wiki.archlinux.org/index.php/Fstab
http://www.pathname.com/fhs/2.2/fhs-5.15.html
tmpfs made Arch a miserable experience since packer and yaourt need a shit-ton of tmp space. It runs out far too quick if /tmp is mounted separately with a statically-sized tmpfs.
You could always unmount /tmp to get around that.
thats weird, i've never had that issue. however, if there was ever the occasion where something from yaourt failed, i never assumed it was because of the tmpfs.
what i don't get is why don't distros use ramfs? that dynamically expands, so you pretty much only use up what you need.
Have they mentioned what video editing and CD/DVD/BD burning programs are supposed to do with their multi-GB temporary files after the switch? Where are we supposed to render our movies and build our ISOs?