Re: [Feedback needed] Setting the right size for /tmp
On Sun, 04 Mar 2012 18:12:09 +0900, Osamu Aoki wrote:
> Hi,
>
> I join too late but ... (I do not use tmpfs for /tmp)
Time does not matter when good feedback comes to place :-)
> On Tue, Nov 29, 2011 at 04:13:05PM +0000, Camaleón wrote:
>> On Mon, 28 Nov 2011 18:07:43 +0000, Camaleón wrote:
>>
>> > I'm running an updated wheezy and today faced with this little
>> > problematic.
>>
>> (...)
>>
>> > Okay, so /tmp is full. Fine. I know how to solve it but I can foresee
>> > more situations like this in the future so some questions arise. As
>> > the current tmpfs default settings for /tmp seem a bit "unrealistic"
>> > (just % 20 of the RAM?) for even doing common tasks:
>
> This is just the default value for RAMTMP=yes in the /etc/default/rcS
> file. You could have much bigger than RAM size as long as you have big
> enough swap to support it. You can do so via /etc/fstab. I once had
> 10GB tmpfs with 4GB RAM so I could have DVD image on /tmp on tmpfs. So
> 20% of RAM is not good enough reason to reject tmpfs :-)
(...)
True, but is still a bad "default" setting, IMO. Neither good for a
system with 132 GiB of ram nor for another with 512 MiB ;-)
Besides, I can give tmpfs a chance (I can see the benefits of using it)
but how could I mimic my current configuration with it? I mean, I don't
like to have to worry for this, so now my "/tmp" -which resides at the
"/" partition- can make use of whatever available space is left on the
disk.
How could I get this setting (that is, "use as much space as there is and
you need") with tmpfs? And will this be desirable or I'm going to have
additional gotchas? :-)
>> Jerome, Bob, Dom... thank you all for your input :-)
>>
>> After carefully reading your suggestions I have decided to disable
>> tpmfs for /tmp and use the old method of having /tmp inside a
>> partition.
>
> Good. As long as you have lots of RAM, most data written to disk stays
> on RAM anyway as cached data if it is very short lived data. So this
> does not slow system.
>
> But that may cause concern for disk wareout if you are using SSD.
Having as little as 2 GiB of ram in this system I can guess tmpfs will help
to speed up things. Yup, I see what can be the benefits of using it... when/
if sanely tweaked.
(...)
>> So, in the end I have set "RAMTMP=no" option at "/etc/default/rcS".
>
> But if you are on laptop with SSD and lots of memory, you may optimize
> diskware by slowing down on disk cache flushing from memory.
>
> http://www.debian.org/doc/manuals/debian-reference/ch09.en.html#_optimization_of_solid_state_drive
Useful and understandable, but not my case. I'm still a bit reluctant in
using SSD disks with the current technology and design.
> Anyway, even for mormal usage, use of noatime in mount option seems to
> be one of the easiest system optimizer.
>
> I stop using huge tmpfs for tmp since it gains nothing for me.
Okay, so no more worries about this. I will keep the old-good default for
"/tmp" then.
Greetings,
--
Camaleón
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