[maemo-developers] [maemo-developers] Zapped wtmp...

From: Nils Faerber nils.faerber at kernelconcepts.de
Date: Thu Apr 13 17:17:06 EEST 2006
Kimmo Hämäläinen schrieb:
> Hi,

> We have a 'temp reaper' daemon for deleting some temporary files that
> have not been used for some time (e.g. temporary E-mail attachments):
> https://stage.maemo.org/svn/maemo/projects/haf/trunk/osso-af-utils/src/temp-reaper.c


> It only seems to clear '/var/tmp' currently. I don't know why we have
> missed the wtmp file...

Interestingly an older firmware image (W48-someting) did not write a
wtmp! Just checked on another not yet updated device.
So this must have been intriduced somewhere between W48 and W52.

> A skilled do-it-yourself man could add '/var/log' there, recompile, and
> replace the binary. It should work if wtmp is not touched too often and
> it's not kept open by any program.

I guess this would not work since wtmp is written to with every close of
the 770 case (for whatever reason). so it will be modified too often -
at least in my case since I open the 770 at least once to 10 times a day.

> BR; Kimmo

> On Wed, 2006-04-12 at 17:34, ext Nils Faerber wrote:
>> Hi!
>> I thought I should let you know...
>> I am not sure if I really found any cure to anything but after the
>> latest discussions about the size of wtmp I checked mine on the 770 and
>> found a more than 200MB file!
>> After gzip'ping it it shrank to just 5MB because it contains almost only
>> 0s. But there must be the information for 200MB stored somewhere in the
>> JFFS2 so I guess that even if it only has 5MB as a comporessed file the
>> impact on a JFFS2 can be much worse.
>> So I enabled the R&D mode, became root and linked /var/log/wtmp to
>> /dev/null (who cares for this wtmp on the 770 anyway?).
>> Before I did this I saw more and more weird phenomena on the device,
>> like crashing browser and spurious power-offs when case closed (almost
>> 100% battery, closed device one night, next morning it was powered off
>> and had to be rebooted!).
>> Now after I zapped wtmp I have the feeling (!) that it behaves much
>> better again! I can browse pages that before did not work and I hope
>> that the power-downs are history now too (for the last three days they
>> are but you never know).
>> Maybe someone else likes to try to this too and report his/her
>> experience here.
>> Probably wtmp should be linked to /dev/null in the next software release
>> too.
>> BTW: With every closure of the case the wtmp grows by about 3kB. You can
>> estimate with your usage how big it will get...
>> Cheers
>>   nils faerber

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