I'd like to make a summary of the discussion (and add my thoughts, I've been
running with my /tmp in tmpfs on several systems for years).
To get something out of the way: if you run your DESKTOP system more than a
week or two, expect /tmp to grow BIG. 2 GB is nothing in my experience.
Thumbnailers sometimes leave data behind and so do things like flash, web
browsers, inkscape, transcoding apps, CD Burners, some compiles ... This
might be due to apps misbehaving but we're not Fedora, we handle the world
as it is - not as it should be.
Limiting the size like Debian does (max 50% of ram for all tmpfs'es) is a
posibility, but then it gets full.
And then? Random crashes, apps refusing to start, horrible slow performance
due to memory running full.
Can we add swap? That is slow. Not just that, by the time the OOM killer
finally decides to kill something in your trashing system, it has been frozen
for an hour if you're lucky. Besides, if it fills up swap you can't hibernate
anymore.
So downside of tmp on tmpfs: we introduce the notion of "have you tried
turning it on and off again?" that MS is just about to do away with (or so
they claim).
Upside of this feature (from Fedora page): a few saved hard disk cycles and
theoretical power savings, most likely quickly outdone by the increased swap
usage. Oh, and we get closer to Solaris, which has been doing this forever.
Yay.
The verdict is simple: we can't follow upstream in this or other distro's in
this. It doesn't work for us.
Debian wants to build an OS for systemadmins. They have to tweak the system
for their usecase anyway. And this is fine for servers, I bet. Fedora wants
people to test the latest and greatest Linux has to offer. Their users are
not supposed to run a desktop/laptop system for a month without upgrading to
new unstable things and rebooting.
But openSUSE wants to build an OS for people who need to get work done, not
fiddle with system internals if they don't have to. Graphics designers,
netbook owners, VM-users, DVD-burning users, flash-users, pdf-viewing people,
web-browsing-users - they all can't work with this...
I think we should pick a sensible default: put stuff which doesn't have to be
in memory, on the disk. Keep the system performant for common usecases.
Those who want their /tmp on tmpfs can use fstab.
If, on one sunny day, the world has been turned around and all apps clean up
after themselves or abuse /var/tmp for the data which wasn't supposed to be
kept over boot (or, in an extremely green/pink world, use the proper
locations like mentioned in Lennarts' blog on this subject), we can re-
consider. And maybe we find other solutions to the problems mentioned - like
cleaning up /tmp once it is getting full or stuff like that. But for now -
let's keep /tmp on disk for at least one more release...
/Jos
* note how I did NOT abuse Lennart Poettering in any way. He's supposed to
invite me for dinner sometime soon and I want to survive his food.