How to set maximum disk cache size?

[Laszlo Nagy]

Ivan Voras wrote:
> Bruce Cran wrote:
>   
>> Wojciech Puchar wrote:
>>     
>>> Laszlo wrote:
>>>       
>>>> Hi All,
>>>>
>>>> Is there a way (sysctl?) to tell FreeBSD (6.2 RELEASE) how many
>>>> memory can it use for caching file data from disk?
>>>>
>>>> It might be that FreeBSD will use all available RAM, and reduce the
>>>> cache 
>>>>         
>>> it already does
>>>       
>> It may seem strange since it's generally accepted that you can never
>> have enough disk cache, but FreeBSD apparently doesn't actually use all
>> the free memory for caching.  By default it uses up to 256MB for
>>     
>
> This is wrong. See
> http://www.freebsd.org/doc/en_US.ISO8859-1/books/arch-handbook/vm-fileio.html
>   
I read this too but I don't understand. Too difficult for me.

So what is the answer? Do I need to set a sysctl or will FreeBSD use all 
available free memory for caching file data from disk?

Thanks,


   Laszlo