/tmp on tmpfs

[Brian Wheeler]

On 04/06/2012 07:47 AM, Marcela Mašláňová wrote:
> On 04/06/2012 11:14 AM, Vratislav Podzimek wrote:
>> On Mon, 2012-04-02 at 20:58 +0100, Richard W.M. Jones wrote:
>>> On Mon, Apr 02, 2012 at 08:32:56PM +0200, Miloslav Trmač wrote:
>>>> * #834 F18 Feature: /tmp on tmpfs -
>>>>    http://fedoraproject.org/wiki/Features/tmp-on-tmpfs  (mitr, 
>>>> 17:40:06)
>>>>    * AGREED: tmp-on-tmpfs is accepted (+5 -3)  (mitr, 18:12:52)
>>>
>>> Actually I think this is a good feature, but ...
>>>
>>> The feature page is wrong about "The user experience should barely
>>> change.  This is mostly a low-level change that has little visibility
>>> to the user."
>>>
>>> tmpfs is different in a number of important ways:
>>>
>>>   - it's very limited in space compared to a real disk
>> This is the reason why I refused having /tmp as tmpfs (or even as a
>> separate partition) few months ago. Has anybody tried to use e.g.
>> Brasero with it? Well, if you are burning a DVD, Brasero needs about 4
>> GB on /tmp -- not enough space in RAM or wasting a lot of disk space on
>> having such big /tmp partition that is most of the time unused. Yes, you
>> can tell Brasero to use some other space, but it obviously relies on
>> volatility of the /tmp and doesn't clean after itself. I'm quite sure
>> this is not only the case of Brasero.
>>
>
> We should file bugs on those issues and add them to some tracker bug, 
> which will be created for tmpfs related issues. Brasero, k3b and 
> applications for scanning will probably need patches.
> I hope some of these bugs were fixed, because Debian already have 
> tmpfs on /tmp.
>
> Marcela

I'm still not convinced that there's any actual benefit from this change 
for 99% of the users.  Filing bugs on anything that uses /tmp because it 
_might_ make a file which is inconveniently large seems more like busy 
work than actually solving a problem.

In the FHS /tmp is only defined as a place for temporary files which may 
not be preserved between reboots.  There is nothing about size and this 
change puts an additional limitation on /tmp which isn't codified 
anywhere and will vary greatly from installation to installation -- 
based on memory/swap size.

Additionally, if programs are leaving large temp files and not cleaning 
them up, then they're putting them in /var/tmp where it will take even 
longer to clean them up automatically.

Brian