[mythtv-users] memory cache problem

[Ray Olszewski]

At 07:07 PM 8/28/2003 -0400, Scott wrote:
>I do not believe this is a myth issue, but am hoping someone can point
>me in the right direction.
>
>When viewing live tv my system crashes after a few minutes.  I have
>discovered this happens when the memory cache + buffer cache + app
>memory consume all available memory (512 MB).  While monitoring this
>during a live tv playback I see the app memory rise about 20% when first
>starting the live tv watching and then it levels off.  However, the disk
>cache keeps going up into it reaches the maximum.  Then it levels off
>for a few seconds and then the box hangs.  I have 400MB of swap
>allocated, but it never touches that.  As soon as I stop watching live
>tv, the buffer frees up.  Can anyone point me in a direction on what
>might be wrong with my configuration that it is causing this?  Can you
>set a max amount of memory to be used for cache?
>
>Any help is appreciated.

You need to explain the problem a bit more exactly. Terms like "my system 
crashes" and "the box hangs" suggest to me more thoroughgoing failures than 
you seem to be experiencing. So be more explicitly descriptive. What 
actually fails? Do just mythfrontend and/or mythbackend stop showing video? 
Do non-myth apps (like top) continue to run at this point? How do you "stop 
watching live tv" is the system has "crashed" (is mythfrontend still 
responsive to keypresses? if so, why call it s "crash"?)?

The caching and buffering you refer to here is a kernel function and is (as 
far as I know) not something you can modify; the kernel simply caches and 
buffers recently accessed executables and files to speed the process of 
using them again.

Although a properly running Myth system will never use swap for any 
recording (it's too slow), I have seen (rare) cases where a system crashes 
(by which I mean dies completely, requiring a reset-button reboot) if RAM 
fills and no swap is available ... so you might want to double check that 
your 400 MB of swap is really available. But, honestly, that's a long shot.

It's probably something else. Can't say what from the little you've 
reported here.