Re: Moving /tmp to tmpfs makes it useless

[Goswin von Brederlow <goswin-v-b@web.de>]

Salvo Tomaselli <tiposchi@tiscali.it> writes:

>> No, tmpfs will be swapped out if you don't use a file for a while but
>> something else uses memory, including IO caching. 
> unless too many things want to use memory, then tmpfs gives a great 
> contribution in taking down the machine.
>
> As you pointed out yourself in another email, under memory pressure the kernel 
> starts doing odd choices.
>
> So the point is: is it correct to enforce a default setting that will break 
> many software that would otherwise work flawlessy, and that makes the machine 
> less reliable but faster for certain kind of tasks?

You're still ignoring that a disk based filesystem puts up the same
memory pressure, even more so for the journal and metadata overhead.

As I pointed out the tipping point can be easily recreated by writing to
NFS. A slow USB device works too if you have one big enough. I haven't
seen the same behaviour with tmpfs but then again I don't put files much
much larger than my ram in /tmp.

MfG
        Goswin